An interesting thing to look at (and a key part of my general election projections) are the shifts from party to party that can be seen in the YouGov data. Some other pollsters also weight by past vote, allowing us to see what percentage of voters parties are managing to hold on to, and which are changing their vote.
The below chart shows how much of their vote the main three parties have retained since January 2011 – (Taken month to month from YouGov/Sunday Times polls)
The thing that jumps out straight away is of course, how much of a hit the Liberal Democrats have taken since being part of the Coalition government. They very rarely hit even 40% vote retention – and this has been consistent for over two years now. Bobbing between 30% and 40% of their 2010 vote seems to signify that the Lib Dems are in core vote territory.
Labour’s vote retention has been fairly steady – there is a recent drop that could go some way towards explaining the current Conservative revival in the polls. It is important to remember that the challenge for Opposition parties is not just to win over voters from other parties – but also hold on to their vote from the previous election.
However, apart from the Liberal Democrat low rate of retention, one other thing stands out – the sharp drop in vote retention for the Conservatives in early 2012, followed by a further drop in early 2013.
Below are the UKIP voting intention figures from the same period:-
The pattern seems fairly obvious – in the same periods that the Conservative do worse at retaining their vote, the UKIP position in the polls improves. There is, quite simply, a direct correlation.
Both Labour and the Liberal Democrats position is too steady to say that they are losing any further votes to any other parties. The Lib Dems obviously had their initial big loss after entering the Coalition, but since then, UKIP do not seem to be making any further inroads into their vote (although they do seem to have taken advantage of the anti-government vote that the Lib Dems used to benefit from).
One of the favourite things for UKIP to say is that they do not just appeal to ex-Conservative voters – well, this may be true, but it’s certainly disproportional. UKIP have improved their vote share by picking up Conservative voters in chunks – and the big question for the Tories is whether that is a permanent shift, or if those votes can be won back.