Over on the YouGov website I’ve written about an experiment we did looking at how the votes might fall in the event that the Labour party did split (the tabs are here). As I say in the article, this needs a thousand caveats – in what proportions has Labour split? Which party is the main opposition with all the publicity that implies? Who is the leader of the anti-Corbyn Labour party, and what sort of policies are they following? How did the split happen? Respondents don’t know, so this can only be a straw in the wind.

The important things to take away are these:

One – there is a sizeable chunk of the Labour vote who are brand loyalists, in the event of a split they would keep on voting for Labour, regardless of whether the left has split away or the right has split away. Just as the faction that is left controlling the Labour party will get the party’s property and assets, they’ll also get that base loyalist vote. Looking at this poll, it seems to be about 28% of the current Labour vote (so about 8% of the national vote)

Two – a lot of Labour voters would go with the left if the Corbyn was somehow ousted and his supporters left. A smaller group of current Labour voters would go with the right if they left, but they’d pick up more support from don’t knows, current Lib Dems and so on. A Labour splinter group of either side would start with around-about 13-14% (again, there are a thousand caveats to this, so don’t take that as set in stone).

Three – the sum total of the support which the two rival Labour parties would be slightly more than the current Labour party (between them they’d get about 34%, compared to Labour’s current polling figures that are around or just under 30%). Under a proportional voting system this might be a good thing. Under First Past the Post this would likely be disastrous for them, splitting the Labour vote and allowing the Conservatives (or UKIP, or whoever) to gain more seats from them. Exactly how bad it would be we cannot tell without knowing how their votes would be distributed geographically, whether individual Labour MPs would be able to retain the Labour vote in their own constituencies. It is likely to be pretty nasty though.

Finally, given the purpose of the exercise was to see what proportion of Labour voters would stick with the “Labour brand” in the event of a party split, we were faced with the problem of what to call the splitters in each scenario. We wouldn’t call them the “anti-Corbyn Labour party” or “Corbyn Labour party” or whatever as the whole point is that they would NOT be the Labour party, we had to give them a new made-up name. But what? In the end we tried it out with various different names to try and cancel out any effect from choosing a compelling or duff name – “Momentum”, “People’s Party”, “Moderates”, “Progress”, “Radicals”, “Social Democrats” – none of the names seemed to make much difference, whatever we called it, the splitters got around 13-15%.

New party leaders normally enjoy a honeymoon in the polls. It’s noticeable for leaders taking over in opposition, on the relatively rare occassion that the party leadership changes hands in government the honeymoon is often remarkable. In the last fifty years there have been three previous occasions when the premiership changed hands between-elections:

• Wilson-Callaghan, 1976. When Harold Wilson announced his resignation in the middle of March the polls were showing a Conservative lead of between two and five points. The polls immediately following Wilson’s resignation and during Callaghan’s first month in office showed Labour leads of between one and seven points, before returning to a steady Tory lead in May.
• Thatcher-Major, 1990. Margaret Thatcher was famously removed by the Tory party in November 1990. In the month before the leadership election Labour had an average poll lead of thirteen points. In the month immediately following her resignation and replacement by John Major the Conservatives had an average lead of five points, peaking at 11 points. Over the next few months the polls settled down to an average Tory lead of four points or so.
• Blair-Brown, 2007. The Blair-Brown handover was a more drawn out affair: Blair announced his resignation at the start of May 2007, when the Conservatives had a poll lead of around six points, and actually handed over to Gordon Brown at the end of June. Through July and August Brown enjoyed an average Labour lead of around five points, peaking in double-digit leads during the Labour conference at the end of September… and their rapid collapse afterwards. The Conservatives were ahead again by October, and remained so for the rest of the Parliament.

Every mid-term change of Prime Minister has been accompanied by a significant boost in polling figures – in the three historical cases, they’ve gone from trailing the opposition to a clear polling lead. The boosts have tended to be comparatively short though – Callaghan and Major only enjoyed a month or so before settling down into a new equilibrium, Brown enjoyed a honeymoon that lasted several months, but that was probably because he was seem to have responded well to the Glasgow Airport attack and Summer floods. There’s no clear pattern as to where the polls settle after the honeymoon: I suppose it depends very much on the leader. Once the honeymoons had passed the change in leader didn’t make that much difference in 1976 and 2007 (in both cases Labour’s position absolutely tanked a few months down the line… but for different reasons), in 1990 though there was a long lasting improvement in Tory support.

So to the current polling position. Today’s ICM poll has topline figures of CON 43%(+4), LAB 27%(-2), LDEM 8%(-1), UKIP 13(-1) (tabs are here). It follows on from an ICM poll last week showing the Conservatives ten points ahead, a YouGov poll giving the Conservtives an eleven point lead and an Opinium poll giving them a more modest six point lead. All four polls had Labour around or just below 30% and the Conservatives nearer 40%, UKIP down a little from the levels of support they’d been showing before the referendum.

Viewed together it certainly looks like the sort of boost a new Prime Minister normally receives, which is a good reason not to read too much into it. New Prime Ministers receive good poll ratings because they haven’t had to annoy too many people yet – the public can project their hopes onto them and convince themselves they really will be different, really will deliver this, that or the other. Before long, however, the shine will come off and they’ll have to start making compromises and disappointing people. This is one good reason for Theresa May not to plan for an early election (and the mistake Gordon Brown made in not shutting down such considerations) – the current polls look wonderful for her, but on past timescales they won’t necessarily be so rosy in a couple of months time. It’s also a crumb of comfort for Labour… though quite a small crumb.

UPDATE: YouGov have fresh voting intention figures that also show a strong lead for the Conservatives, albeit, not quite as big as ICM’s. Their topline figures are CON 40%, LAB 28%, LDEM 8%, UKIP 13%, GRN 4%. Tabs are here

The Times this morning has updated YouGov polling of Conservative party members, now that the final list of candidates is known and ahead of the first MP’s vote today. A week ago YouGov had Theresa May leading on 36% to Boris Johnson on 27% and winning by 55% to Johnson’s 38% in a head-to-head contest. Since then Boris Johnson’s campaign has imploded and he has dropped out the race, so where do we stand now?

Asked their first preference Theresa May has the support of the majority of members, with 54% support compared to 20% for Leadsom, 9% for Gove, 5% for Crabb and 5% for Fox. Note that Michael Gove has gained little of Boris Johnson’s support, rather it is Andrea Leadsom who has taken over as the leading “Leave candidate” (in fact Gove’s behaviour appears to have utterly shattered his popularity among Tory members – a week ago 63% had a positive view of him, now it is down to 32%). In head-to-head contests May beats all comers with ease, but it is again Leadsom who comes closest. In a May-v-Leadsom final round May would win by 32 points, she would beat Liam Fox by 50 points, Gove by 51 and Crabb by 63.

Theresa May leads in every demographic group. Among members who voted to Remain she absolutely dominates, among members who voted to leave she beats Leadsom, but relatively narrowly. If the race becomes tightly focused on whether the candidates voted Remain or Leave, and Leave voters line up more strongly behind Leadsom it could get interesting… but currently Leave voters say they consider competence as PM and ability to unite the party as more important than how the candidates voted in the referendum, and in both areas May has a strong lead.

For the time being May is in a dominant position, but the fact that Leadsom is little known is in some ways an advantage: she doesn’t have negative perceptions to shed and Leave supporters can paint all their hopes onto her. If it’s a race about party unity and leadership, May has a strong advantage – she takes support from both Remain and Leave, and is seen as by far the strongest leader, the most suitable for the job of PM and the best in a crisis. If it boils down to Conservative party members looking for someone who voted Leave…

Full tables are here.