Lord Ashcroft poll of marginal seats
Lord Ashcroft has repeated the same sort of large marginals poll that PoliticsHome did in 2008 and 2009, looking at the clusters of key marginal seats that will provide the battleground for the next general election.
As in 2008 and 2009, the poll asked two questions to determine voting intention - asking the same sort of standard voting intention that all polls use, then prompting people to think about tactical voting, asking people to think specifically about their own constituency, the political situation there and the candidates likely to stand and then asking how they'd vote in their own seat.
There is a widespread belief that people don't really think about tactical voting until a general election is almost upon us. I'm not so sure that's the case, it may just be that people don't reflect their tactical voting intentions in polls until late in the day! The two-stage voting intention question clearly suggests that some people answer a standard voting intention question differently to how they think they would actually vote in a general election, their normal answer is more like their "national party preference".
Anyway, this two stage voting intention appears to pick up tactical and incumbency effects, so in Labour held seats it tends to slightly increase the reported level of Labour support, in seats the Conservatives are defending it marginally boosts Conservative support. Where is has a massive effect is in Lib Dem held seats - the Liberal Democrats get much more support in those seats when you prompt people to think about their own constituency.
The picture painted by the Ashcroft marginal poll is not particularly surprising - a big swing from Con to Labour, the Liberal Democrats collapsing where they are against Labour but more resilient against the Conservatives. It is good to have solid data to back up what I was only assuming was happening in the marginal seats though!
The swing from Conservative to Labour is slightly smaller in the marginals than in the national polls (national polls are showing a swing of around 8.5%-9.5%, while this poll shows a swing of 8% in Con-v-Lab margins) but this looks like this is the result of incumbency effect for those first term Conservative MPs who hold most of those seats - the standard voting intention question without the constituency prompt was showing a swing wholly inline with national polling. There are no massive regional differences, the biggest being London marginals where there is only a 5% swing from Con to Lab, probably a reflection of the fact that the swing towards the Conservatives in London in 2010 was much less than elsewhere in the country - there is less far for the pendulum to swing back.
Perhaps the more interesting findings are what the poll says about the Liberal Democrats - the Con-v-Lab battle normally follows national polls, the Lib Dem battleground is sometimes different. When PoliticsHome asked the two stage voting intention question structure back in 2009 it found the Lib Dems did 10 points better in LD-Con seats when people were prompted to think about their own constituency (and conseqently was actually quite a good pointer to how well they'd do at the 2010 election - it had them getting 55 seats, compared to the 57 they actually got). In the Ashcroft poll today the tactical/incumbency boost the Lib Dems get in LD-Con seats when people are prompted to think about their own constituency is a mighty 13 points.
This is naturally good news for the Liberal Democrats, but still means they will lose a lot of seats. The reason that tactical/incumbency boost is bigger is probably simply because they are starting from a much lower base. Even with this prompting the poll suggests the Lib Dems will lose around 17 seats to the Conservatives. In seats where they are
up against Labour the swing is bigger, the tactical/incumbency boost is smaller, and the Lib Dems face wipeout. Overall, if this poll was reflected at the next general election - still two years away remember- it would leave the Lib Dems with around 25 seats, a very sizeable loss, but not the complete wipeout that some have
predicted, feared or hoped for.
