As well as the Scottish polling there was also a YouGov poll of Lib Dem members yesterday, conducted following the local election results. YouGov surveyed 396 panellists who identified themselves as current Liberal Democrat party members, and 118 who had previously told us they were members of the party but had since left. Full tabs are here.

There were large majorities of party members thought that Chris Huhne and Vince Cable were performing well in office. There was similar backing for the Prime Minister, David Cameron. Liberal Democrat party members were, however, evenly split over Nick Clegg – 50% think he is doing well as Deputy Prime Minister and Leader of the Liberal Democrats, 50% think is is doing badly. Asked about his future, 45% think he should remain leader of the party at the next general election, while 35% think he should stand down at some point before the election

Turning to how well the Coalition Government is managing various issues there was strong support for the Government’s handling of taxation (75% thinking the government had done well) where the Liberal Democrat aim of increasing the personal allowance is being implemented. 67% also thought the Government was managing public spending well. A majority of Lib Dem party members also thought the Government was doing well on crime, Europe, overseas aid. Predictably, a large majority – 77% – thought that the Government was doing badly on student fees. Lib Dem members were almost as unhappy about the Government’s NHS policy, where 73% of party members thought the Government was doing a bad job.

Despite these misgivings, overall 79% of Lib Dem members viewed the Coalition as having been good for Britain. 88% thought it was good for the Conservative party… but 66% thought it had been bad for the Lib Dems (including 21% who thought it had been disastrous). Despite this, a large majority (91%) thought that joining the Coalition was right, and 57% thought that the right deal had been struck under the circumstances

There is hardly any support amongst Liberal Democrat members for ending the Coalition – just 7% want to pull out now, and 6% to pull out in a year or two’s time. 63% of party members want to see the Coalition last for the full five year term of the Parliament.

While these figures represent overwhelming support for the Coalition among Lib Dem members, it is worth remembering that these represent only the responses of those people who have remained in the party. Many Liberal Democrats who opposed the Coalition may have resigned or failed to renew their memberships – among those respondents we contacted who are no longer members of the party, 35% opposed the Coalition and 40% think the party should leave the Coalition within the next year or two.

Tonight’s YouGov/Sun voting intentions are CON 39%, LAB 41%, LDEM 9%. While there is the normal variation from day to day, we’ve now had three YouGov polls in the last week showing the Labour lead down to 2 – it looks as though the local election may have lead to a slight narrowing of the polls.

The collapse in Liberal Democrat support since the election is startling. At the general election they recorded 24% (having hit 30%+ in some campaign polls, though we will never know for sure how much of that was down to polling error). By the end of the year, most polls showed them losing at least half their election support and in the case of some YouGov polls up to two-thirds.

The reasons why Liberal Democrat support has collapsed are fairly obvious. A Populus poll of people who voted Liberal Democrat in 2010 in Lib Dem seats asked people in their own words why they voted Lib Dem and how they think they will end up voting at the next general election. In Populus’s poll the main reasons people gave for voting Lib Dem were believing in their values or principles, because they rated their local Liberal Democrat MP, because they thought it time for a change or didn’t like the main two parties, or as a tactical vote against Labour or Conservative.

As one can imagine, at least three of those reasons are now somewhat problematic – People who voted for the Liberal Democrats seeing them as a centre-left party pursuing liberal or social democratic policies may be unhappy seeing them working with a right of centre government (42% don’t think they will end up voting Lib Dem), people who voted for them as an idealistic alternative to the main two parties may not be happy seeing them working hand-in-glove with one of them (49%-50% don’t think they’ll vote Lib Dem next time), people who voted for them as an anti-Conservative tactical vote will obviously be less than chuffed (68% don’t think they’ll vote for them next time). The most loyal voters are obviously those who voted on the basis of their high opinion of the Lib Dem MP – but even there only 64% think they’ll remain loyal.

Unsurprisingly the main divide seems to be whether voters approve or disapprove of the coalition – most (but not all) of those Lib Dems voters who think the coalition was the right thing to do think they’ll back the party again, most (but not all) of those who disagree with the decision think they’ll end up voting for someone else.

If you look at where the lost Liberal Democrat support has gone (and I’m looking now at standard polls asking how people would vote tomorrow), the biggest chunks have gone straight over to Labour, or are saying they don’t know what they’d do at the next election. In YouGov’s final poll of the year only 24% of people who said they’d voted Lib Dem in 2010 said they’d support the party tomorrow, with 25% saying they’d vote Labour and 25% saying don’t know (the remainder split between voting Tory, Green, other parties or not voting at all).

The large chunk of former Lib Dems saying they don’t know what they’d do in an election tomorrow is, incidentally, a major reason behind the wide variance in the level of Lib Dem support different pollsters are showing. YouGov have tended to show the lowest levels of support with around 8 or 9 percent in their latest polls. ICM have tended to show the highest levels of support for the Lib Dems, with their last poll of the year showing them on 13 percent. Part of the reason for this is don’t knows – even ICM only actually find 11% of people saying they’ll vote Lib Dem – the 13% comes about because, based on past performance, ICM assume half of those former Lib Dems now saying don’t know will end up voting for the party in the long run.

Whether that turns out to be the case or not, it’s worth remembering that a fair chunk of those lost Liberal Democrats haven’t gone to Labour, or to minor parties or anywhere – they just don’t know what to do. Those people may yet defect to other parties or sit on their hands, or they may be won back for the Lib Dems in the fullness of time.

So what can the Lib Dems do to try and win those voters back? There are no easy answers. Some voters are probably out of reach for the time being – the Lib Dems used to win both anti-Labour and anti-Conservative votes, they are unlikely to be able to play both sides in the future. The second problem is that the Liberal Democrats could previously be a purist party that said all the right things, unburdened by the unpleasant compromises of government. A colleague characterised it to me as the Lib Dems fighting the last general election as if they were a virtuous maiden standing against two grizzled old whores, yet having got into government people have suddenly realised they were just like the other two. In a similar vein, the Lib Dems have often been able to trade on the popularity of their leaders – in 2001, 2005 and especially 2010 the Lib Dem party leader had the highest approval rating, Clegg now has the lowest approval rating.

The view of the Liberal Democrats seems to be that they need to highlight where they have made changes to government policy and to champion the more Liberal policies being introduced. This is probably right in principle, as polls increasingly show people are no longer sure what the Liberal Democrats stand for. As early as August 61% of people were saying it was “not very clear” or “not clear at all” what the Liberal Democrats stood for and YouGov’s regular trackers of party image have shown the proportion of people who think the description “It seems to chop and change all the time: you can never be quite sure what it stands for” applies best to the Liberal Democrats has gradually grown from 24% just after the coalition was formed to 36% now.

That doesn’t mean it is easy to do though, going back to the Populus poll of Lib Dem voters in Lib Dem seats, Populus asked whether people thought the Lib Dems had made a positive impact in various areas of government policy. In no case did more than a third of respondents think that the Lib Dems had made a positive difference to government policy – the highest was on welfare reform, where 32% said that the Lib Dems had made a positive difference, 26% thought they had made a positive difference on the spending cuts, in most other areas less than 20% thought the Lib Dems had made a positive impact. Remember this was a poll of Liberal Democrat voters in seats with Lib Dem MPs – these are the people most likely to think positively of the Liberal Democrats and be receptive to their messages, if even a chunky majority of them think the Lib Dems are not making a difference, then the party are clearly struggling to get the message across.

Looking at the threats and opportunities for the Lib Dems next year we have the Oldham and Saddleworth by-election. Labour are now the very strong favourite, but until we see some polling (and a company called Survation is apparently currently conducting one) I’m wary about writing the Liberal Democrats off. Recall the Dunfermline and West Fife by-election, fought at a time when the Liberal Democrats were polling almost as badly as they are today (they had just jettisonned Ming Campbell and stood at 11% in the polls), they still managed to win the by-election from Labour on a hefty swing. It would be a big boost to the party if they pulled it off. (as someone has pointed out in the comments, I’ve mixed up my Lib Dem interregnums – Dunfermline was after Charles Kennedy’s ousting, not Ming’s, and the Lib Dems weren’t in such a bad way.)

Secondly there are some policy areas that are due to be dealt with that they may be able to point to as Lib Dem achievements – such as House of Lords reform, control orders, or taxes on bankers (some of these things risk being the cause of arguments within the coalition too!)

Thirdly there are the local elections and the AV referendum in May. The local elections are likely to see the same sort of hefty losses for the Lib Dems that I predicted for the Conservatives yesterday. That brings us to the AV referendum – if it is won, then the Liberal Democrats will have something utterly solid they can tell their activists and supporters the coalition has delivered, if it is lost, then it will be a further blow to Lib Dem morale.

Is there a point when the Liberal Democrat position in the polls gets so bad they withdraw from the coalition (or the party splits?) – I don’t know, I don’t pretend to have any great insight into the views of Liberal Democrat MPs or activists. My guess is that the chances are greatly overestimated by people who would like it to collapse (the truth is I think we all overestimate the chances of exciting and interesting things happening!). Being outside the coalition wouldn’t necessarily help the Liberal Democrats much in the polls (it would give them the independence to promote their own policies, but the damage to their image has already been done) and the last thing the Liberal Democrats would want to risk in their present situation is an early election. I expect, like the Conservatives, Nick Clegg’s strategy is dependent upon seeing the job through until the economy has recovered and then pointing to what the Lib Dems have achieved and contributed to that.

When writing these round ups I try to present the good and the bad news. By necessity, this has ended up as a very pessimistic piece for the Liberal Democrats, though what can you do for a party that has lost half its support within a year? The harsh truth is that it’s not easy to see a light at the end of the tunnel for the party. So for a more optimistic point of view, I’ll leave you with a quote from Mark Pack (personally I think a by-election victory would be more likely to change things than scrapping control orders, but there goes – Mark’s pieces on the 2011 challenges for the Lib Dems are also highly recommended):

“Imagine if at the end of next month control orders had been scrapped and there was Lib Dem MP for Oldham East and Saddleworth. The political landscape would look very different.”

Tonight’s YouGov poll for the Sun has topline figures of CON 41%, LAB 41%, LDEM 8%. It’s the lowest Lib Dem score YouGov have ever shown, and as far as I can tell the lowest Liberal Democrat score any pollster has shown since September 1990, over 20 years ago.

I’ll add my normal caveats about not getting too excited about a single poll, new extreme highs and lows for parties do tend to be the outliers, but nevertheless, the fact that we’ve got our first 8% for the Lib Dems suggests that their support is still on a downwards trend. It is probably no co-incidence that this comes after several days of the Liberal Democrats internal ructions over tuition fees have been all over the political headlines.