It’s a truism that there isn’t one election on May 7th, there are 650. However, the brutal reality is that lots of them will behave much the same in terms of swing, and that in lots of them the outcome is a virtual certainty and they won’t matter. A good 450 or so seats we can be pretty confident won’t change hands this Thursday unless the polls are very wrong. We can actually boil down the election to four battlegrounds. Here’s where they are and what we know about them from the polling so far.

Conservative vs Labour battleground

Conchart2

The main battleground in determining which party will lead the government is that between Labour and Conservative. It’s also by far the largest – it’s true to say that the political geography of Britain has become ever more diverse since the days when almost every race was just Lab-v-Con, but the biggest single chunk of winnable marginals is still just that.

It’s also the battleground where good old uniform national swing remains a fairly good guide. It won’t predict individual seats – there will always be some seats with much bigger swings, some with more smaller ones – but in aggregate it should give a good picture. Overall current polls show a swing of about 3% or 3.5% from Conservative to Labour. In the Con-Lab battleground that should win Labour roughly forty seats.

However, there are two important caveats to this. The first is that almost all the Con-Lab battleground is in England & Wales, and GB polls are distorted by the completely different swing in Scotland. Labour’s vote is up by around 5 or 6 points in England & Wales, down by about 15 to 20 points in Scotland. If you look at the data in just England & Wales you find a Con>Lab swing nearer 5 points, which would win Labour around sixty seats.

The second is whether the swing in the marginal seats is the same as the swing in England and Wales as a whole. Looking at the historical data there is good reason to expect it won’t be. The vast majority of the Con-Lab battleground seats are being fought by first time Conservative incumbents who won the seat in 2010, this means they will be gaining an incumbent advantage they didn’t have last time, while in many cases Labour will be losing an incumbent advantage they enjoyed in 2010. Looking at data from past elections this impact is pretty consistent even if it is worth only a couple of percentage points (it’s worth far more for the Lib Dems). There is some evidence to support this – the recent ComRes poll of Con-Lab marginals found a swing of 3.5%. Looking at the broad sweep of Lord Ashcroft’s polls in these seats and adjusting the older Ashcroft polls to account for changes in the national polls since they were done the average swing comes out around 3.8%.

In practice this means the swing in the Con-Lab marginals may well be similar to that in the national polls, but only because Labour’s over-performance in England & Wales is cancelled out by Conservative over-performance in Con-Lab marginals. That means Labour gains from the Tories of around 40 seats, if the national polls are neck-and-neck (if the Conservatives are a point or two better, the gains will obviously be less)

Of course there will be variation between seats, so not all Con-Lab marginals with majorities below 7% will fall, there have been some constituency polls suggesting good chances of Conservative holds in marginals like Loughborough, Worcester or Kingswood. Equally though there will be some seats with larger majorities that do fall – London constituency polls in particularly have shown larger swings, so watch for places like Ealing Central & Acton or Finchley & Golders Green.

The SNP Landslide

SNPchart

The second biggest focus on election night will probably be the Scottish seats. What the story will be in Scotland is not in dispute, it will be a SNP landslide. The question is only the scale of that landslide. All the polling evidence gives the SNP a very large lead, varying between 20 and 35 points. The questions are where it ends up in that range, how accurate it is and how it translates into seats.

To deal with the overall polls first, I can well imagine that some polls in Scotland will overestimate SNP support. There have been huge shifts in party support since previous elections (and probably significant changes in the drivers of voting intention in Scotland) making it hard to model and weight Scottish samples. Equally SNP support is extremely enthusiastic – I can well imagine differential response rates becoming a problem. That said, polling error in Scotland probably won’t cause much of an upset because of the sheer size of the SNP lead – to put it bluntly, if polls give a party a 5 point lead and it turns out its actually a draw then it makes a huge difference. If polls give a party a 25 point lead and it turns out that lead is actually only 20 points it is not, in practice, such a big deal, even if the scale of the error is the same. The difference will only be between “vast landslide” and “huge landslide”. I cannot see the polls being so wrong that the SNP don’t get a crushing victory.

So how will the SNP landslide in votes translate into seats? Well, with a swing of this scale Uniform National Swing really does break down completely. UNS assumes parties shares of the vote go up and down by the same amount in each seat, but Labour cannot lose 20 percentage points in every seat in Scotland, it would give them a negative share of the vote in nine seats. The same applies to the Liberal Democrats. As a result of this floor effect, Labour and the Liberal Democrats must be losing more support in seats where they had more to begin with – their vote has fallen too much to be evenly spread across all of Scotland. This means that Labour and the Lib Dems could lose even more seats than suggested by uniform swing (and means even if the national share of the vote for the SNP isn’t as good as polls suggest, they could still get the sort of landslide in seats that the polls suggest).

The scale of the SNP surge is such that very few seats have any realistic chance of withstanding it. The most plausible ones are the very largest Labour majorities, the Glasgow North East, Kirkcaldys of the world, Jim Murphy in Renfrewshire East, the Lib Dem stronghold of Orkney & Shetland and perhaps the border seats (if the SNP don’t take Berwickshire, it is also a marginal between the Lib Dems and Conservatives).

Liberal Democrat Defence

LDchart

Given the Conservative party’s most viable coalition partner is the Liberal Democrats how many seats change hands between the two parties doesn’t make much difference to the electoral maths after the election. It is still obviously important for negotiations, party morale, the psychologically and politically important issue of who is the biggest party (and, of course, for who is the MP in those seats!). Liberal Democrat battles against Labour are far more important in terms of the hung Parliament maths.

The Liberal Democrats’ ability to win and hold seats has a famously limited relationship with their national vote share. In 1992 they got 18% of the vote and won 20 seats, in 1997 their vote went down to 17% but they more than doubled their number of seats to 46. In 2010 they gained votes, but lost 5 seats. How many seats they win has always been largely reliant upon their ability to harness tactical and personal votes in their areas of strength. That said, it’s not realistic to expect a party to lose half their national support and emerge unscathed. While I’ve seen a few claims for potential Lib Dem gains that aren’t completely ludicrous (Watford or Maidstone & the Weald, for example), generally speaking the Liberal Democrat election aim is to limit their inevitable losses as much as they can. This depends upon the demographics and political opponents in their seats, and the incumbency and entrenchment of their individual MPs.

In England and Wales the Liberal Democrats have 46 seats. In eleven Labour are the second placed party, in thirty-four the Conservatives are second placed (though in at least two of them, Sheffield Hallam and Cambridge, Labour are probably the bigger threat) and in Ceredigion Plaid Cymru are second placed. In the vast majority of the seats we have individual polls from Lord Ashcroft to give us an idea of how the race is looking. There are two extremely obvious trends – one is that the Liberal Democrats are collapsing where their main challenger is Labour, but holding up well where the main challenger is the Conservatives. The second is the sheer variation between seats, even within the LD-Con battleground and the LD-Lab battleground.

Ashcroft has polled all the LD/Con marginals that might feasibly change hands. The average swing in these seats was just over 2 points from LD>Con, enough to take about seven seats. However the swings ranged from ten percent LD>CON in Chippenham, to swings of seven percent from CON>LD in Eastbourne and Sutton & Cheam, and in practice this meant ten of the constituency polls had the Conservatives ahead – but these are just snapshot polls with margins of error, so many of these seats are in play. Note also, that many of the polls were last year and the Liberal Democrats have recovered slightly since then.

Looking at the LD-Lab battleground the average swing was a crushing 12 points from LD>Lab, meaning many of these seats are almost nailed on certainties for Labour. The exceptions are Birmingham Yardley, where John Hemming polled surprisingly well, Bermondsey where Simon Hughes was protected by a huge majority, Cambridge and Sheffield Hallam where Labour are coming from third and I expect the Lib Dems will benefit from tactical voting (Ashcroft showed Clegg behind in Hallam, but more recent ICM polling has him ahead). Hornsey and Wood Green is also interesting – the Lib Dem own polling has them doing better there and both the Lib Dems and Labour seem to be targetting it heavily, so it may be much more of a toss up than Ashcroft suggested.

UKIP Targets

UKIPchart

There is no easy way to come up with a list of UKIP targets – demographics, local and European election results can give us a steer, so can some of UKIP’s published statements about which seats they are targeting. Realistically though when a party has more than tripled their vote it is hard to accurately judge where their positions of strength and weakness are. The seats below are my best guesses of their most plausible gains (there are other seats where they have strength like Waveney, Great Yarmouth or Redcar that are in the Con-Lab battleground list… but I don’t think they stand much chance of actually winning any others, and constituency polling in some of those seats has shown them on the wane. As to how they will do in these seats – I don’t think any are necessarily easy to call. Everyone assumes Douglas Carswell will hold Clacton given his margin of victory in the by-election, Mark Reckless in Rochester looks more vulnerable. Thurrock looks too close to call, as does Thanet South with its contradictory polling. Great Grimsby was a plausible UKIP gain, but recent polling has Labour with a healthy lead. Polling commissioned by UKIP donor Alan Bown gave them a stonking lead in Boston & Skegness last year, but this year an Ashcroft poll found the Tories ahead. My own guess is that Clacton will probably be a hold, and they have a chance in these other seats… but they won’t strike home in all of them.

And the rest

That leaves a few other interesting seats that don’t fit into any of the main battleground categories, but could change hands. Two are the seats held by smaller parties – I expect the Greens to hold on in Brighton Pavilion (but not gain anywhere else), how George Galloway will do in Bradford West is anyone’s guess. Watford appears to be the only Con-Lab-LD three way marginal that is still a three way marginal for the three parties – it could go either of the three ways.

And so, a prediction

I generally hold to the pollsters’ maxim of snapshot not prediction, so I avoid predictions like the plague for most of the Parliament as the polls may yet change. In 2010 I waited until after the final polls were done before getting off the fence, but it gave me very little time to actually write anything, so this year I’ve done it up front. Obviously if Wednesday’s final polls do show the Conservatives eeking out a small lead I’ll reconsider and make my prediction more Conservative – when the facts change, I changed my mind. As it is though, my personal best guess is Conservatives around 277 seats, Labour around 267, the Lib Dems around 29 and the SNP around 52. I’ll revisit those once we have the final polls.


742 Responses to “The election battlegrounds… and a prediction”

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  1. @Laszlo @Magpie @V Lenthan

    You’ve eased my worries a little!

    This is the article claiming Chipping Barnet isn’t safe any more – http://wwwbrokenbarnet.blogspot.co.uk/2015/05/playing-orator-campaign-trail-continues.html (I think I read another one the other day but can’t find it any more).

    VoteSwap, which appears to be a left-wing vote-swapping site, is also claiming it will be a ‘semi-marginal’ – http://voteswap.org/seat/i65886

  2. JACK SHELDON

    Got that. :)

  3. Here’s my prediction

    Lab 285
    Con 280
    SNP 48
    Lib 20
    Others 17

    I think the Libs might actual get a few more, but I placed a bet on 20 or less at 5 to 1, which is skewing my judgement.

  4. 5 polls in, 3 Con leads and 2 level pegging.

    Single phone poll with a Con lead

    4 Online polls, 2 Con Lead & 2 level pegging.

  5. Have enjoyed all your posts, very enlightening to read all opinions and facts and predictions.

    Here is mine

    Con 282
    Lab 265
    SNP 47
    LD 27
    DUP 8
    UKIP 7
    SF 4
    PC 3
    SDLP 3
    Alliance 2
    Ind 1
    Speaker 1

  6. PA3YRE

    Ah, do you need a different time. I notice you normally post at about 2am (here) or so.

  7. Just for clarification, members of HM Armed Forces when posted abroad are eligible to vote in the UK and those from Scottish Constituencies were also eligible to vote in the referendum

    As for non resident status re tax, I also think there is some confusion. As a non resident myself I have no choice as to my status as I work abroad for 12 months, but I still pay UK tax on my UK pension, as well as property income.

  8. Some of the forecasts on here are bonkers. Firstly, to assume that the Tories will be the largest party, you have to assume the following;

    – All the polls are wrong
    or
    – The polls are right but it’s much closer in the marginals, which would obviously have to be balanced by really large swings elsewhere
    or
    – There is going to be a magical late Tory surge due to…ahem…reasons unknown

    With the Labour vote squeezed in Scotland, neck-and-neck means a large swing in England/Wales. As the Labour vote is static in Wales, it really means a large swing in England.

    So what is going on? Do people simply not believe the polls? Do they think it’s 1992 all over again despite no evidence of Labour over-estimation in the polls in recent elections?

    For the 2010 general election, Labour out-performed their polling average by 2 points. I just cannot understand how any sensible person can safely assume that the Tories will be largest party. Maybe they will be, but it doesn’t show in any actual evidence.

  9. TT

    Have your prediction :)

  10. @ Jack

    The vote swap site actually think that Chioping Barnet is safe Conservative, only the language is coded :-)

    But there will be a number of constituencies where it will be about the minor parties (even though they have been squeezed).

  11. 345 race at Chester today -with a furlong to go Come on Dave was in the lead but….
    finished fourth.

  12. Come on Dave came in fourth in the 345 at Chester today -was leading but ran out of puff.

  13. Odds Checker now has DC as favourite for PM based on the averages of all the bookies…..was worth a punt a few weeks ago then. If that comes in it will have to hold me over as the only good news until 2020!

  14. @DrMibbles

    Forecasting just a bit of fun really… wouldn’t be much fun if we just tapped the current poll average into May 2015 and posted what we got out.

    But as AW says in the opening post the CONs are likely to perform better in the marginals than elsewhere… only slightly but enough to make a difference… and most academic forecasts do narrowly give the Tories most seats. We’ll see how it comes out.

  15. DRMIBBLES

    The predictions are for fun. In the spirit of the site no derogatory comments please!

  16. Re the late surge in the Lib Dem vote; I’m hearing that it’s down to a complete u-turn by Nick Clegg on one of the key issues from the past few days. It seems that he IS going to have Katie Hopkins killed after all. Odds on a Lib Dem majority are still 1000-1 so get in there quick!

  17. @DRMIBBLES

    It’s because many (most?) are wishful thinking betraying the hopes of the individual poster rather than an interpretation of the polls.

    But

  18. Glad I put my money on the real DC rather than the one at Chester then!

  19. Her Majesty’s civil service seems to be weighing in by calling to order the subjects who are opining about legitimacy.
    Will Clegg and Cameron tell them where to put the manual or demand a rewrite?

  20. @RobertNewark and jstephenson

    Just to clarify. A person could vote in the independence referendum if they were registered to vote in the Scottish Parliamentary elections ( together with an extension to 16 and 17 year olds). Service personnel abroad can register to vote in the normal way or through a specific registration process to them.

  21. ‘LAGAVULIN
    Re the late surge in the Lib Dem vote; I’m hearing that it’s down to a complete u-turn by Nick Clegg on one of the key issues from the past few days. It seems that he IS going to have Katie Hopkins killed after all. ‘

    I’ve changed my mind about which party to vote for now – LD here I come!

  22. I think swingback has started – in Scotland. Opinium’s 13% SNP lead could be a harbinger. It will be interesting to average all the Scottish cross breaks in these last 10 or so polls. That should give an MOE of around 1%.

    Maybe Sturgeon has overreached.

  23. Latest Forecasts (according to Wiki)

    Election Forecast Con 281 Lab 267
    Electoral Calculus Con 280 Lab 276
    Elections Etc Con 289 Lab 257
    Guardian Con 274 Lab 270
    May 15 Con 273 Lab 269
    Sporting Index Con 289 Lab 265
    FPTP Con 279 Lab 270

    This gives an average of Con 280.7 Lab 267.7
    or if you exclude the highest and lowest Con 280.6 Lab 268.3

    So my question is, how small does the “legitimacy gap” (1) have to be before the larger party admits that it is effectively a tie?

    1. Legitimacy Gap is in the Magna Carta. I looks it up in the Daily Mail book of the British Constitution [sic].

  24. Like so many, I just want to offer my sincere congratulations to Mr Wells for his superb management of this most excellent site.

    Also to CATOSWYN for running his prediction comp!

    And my guess…

    Lab 275
    Tory 272
    SNP 49
    Lib/Dem 29
    DUP 9
    SF 5
    SDLP 3
    PC 3
    UKIP 2
    Green 1
    Independent 1
    Speaker 1

  25. LITTLEREDROCK

    Magna Carta…sounds a bit foreign to me.

  26. @CATOSWYN

    No that would be cheating! I work European hours anyway.

    Means I can set my alarm for 8am and watch the results come in at my leisure though.

  27. My prediction for whole HoC:

    Con 279
    Lab 269
    SNP 53
    LD 21
    DUP 8
    SF 5
    UKIP 4
    Plaid 4
    SDLP 3
    Green 1
    UUP 1
    Independent 1
    Speaker 1

    If it does end up anything like that, potential voting blocs would be interesting. It would be all about the SNP. The Conservatives would obviously be unable to cobble anything together, but Labour might need to rely on direct LD and SNP support (rather than just abstention) to pass their own Queen’s Speech and legislation.

  28. @littleredrock.

    I would say, and already have, anything much more than a 10 seat Tory advantage makes Labour governing look a little shady – from a public view, not political and definitely not a constitutional point of view.

    Even if its 1 seat advantage DC will try and hang on – he won’t but he will try.

    10 seats or less it’s a tie in my eyes.

  29. BIGFATRON

    Have your predictions ;)

  30. @ Hawthorn

    Magna Carta! Did she die in vain?

  31. Little Red Rock

    10 seats would not raise a legitimacy question for me,
    I suppose share of the vote may also be considered.

    From a Tory perspective, 280 seats would be a major disappointment,
    290-95 plus completely different – that’s why it’s so exciting )

  32. POPEYE

    Got that :)

  33. @ Bluemoby

    I know what you mean but numbers and people being a bit weird the great British people may think 271 – 279 is a tie but 267 – 275 isn’t

  34. If the Tories win less than 280 seats, then for me Labour have
    effectively won the GE.

    That’s from my Tory perspective,

  35. DRMIBBLES

    As you ask…..

    My highish Tory prediction is based on history, the 1992 effect and wishful thinking. I think Crosby is probably right and has concentrated on the right issues, the SNP is an unforeseen bonus.
    The UK hasn’t elected a left wing government since 1974 and then only just. I think the polls are right today but tomorrow enough voters where it matters will pause and then make their choice on the following…
    Cameron or Miliband as PM
    Cameron as PM or Miliband as PM told what to do by SNP
    Economy just about ok but not good enough to hand over to Labour to screw up again.

  36. @Sunreada

    “Come on Dave came in fourth in the 345 at Chester today -was leading but ran out of puff.”

    That’s “neigh” good.

  37. @drmibbles

    ” I just cannot understand how any sensible person can safely assume that the Tories will be largest party.”

    Anthony Wells seems sensible to me

    Chris Hanretty and various other academics also seem sensible

  38. @ Phil White

    Thank You, that’s interesting.

    Both posts, I mean.

  39. @Little Red Rock

    That outcome would be the result of Labour school standards (dumbing down GCSEs etc,).

  40. If this was a poll it would be an outlier but…

    Con 330
    Lab 220
    SNP 50
    LD 25

  41. THE MONK

    Have your prediction :)

  42. @The Monk,

    I understanding Crosby is forecasting Con 330.

  43. @Little Red Rock

    BTW, I’m referring to your 271-279 vs 267-275 remark.

  44. DRMIBBLES

    I could add incumbency, higher Tory turnout as it is close, soft UKIP votes breaking more to Tories then Labour.

  45. @Sunreada @KeithP
    “Come on Dave came in fourth in the 345 at Chester today -was leading but ran out of puff.”
    That’s “neigh” good.

    Not much chance of a “stable” government afterwards. Certainly not one that will last “furlong”

  46. @little red rock

    “I understanding Crosby is forecasting Con 330.”

    I think he’s predicting 300

  47. I thought that it would be a dead giveaway to register as LYNTONC

  48. ‘MBRUNO
    @Little Red Rock
    That outcome would be the result of Labour school standards (dumbing down GCSEs etc,).’

    Tories did that… And frankly ‘dumbing down’ is not the right question. The point of exams is how accurately they rank students in order for Universities and employers. It actually does not matter if an A today means the same as an A ten years ago…

  49. Are the legitimacy claims because it’s the SNP who might prop up Labour? I was wondering (hypothetically obviously) if is was Cons 280 and Lab 260 but it was the LibDems who had 50 MPs and wanted to support Labour, would we have the same claims being made.

  50. 30 hours to go until polls closed. Any advices to calm down my nerves? Watching football tonight last for only 2 hours.

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