Survation/Mail on Sunday show Tories 4 points ahead in Eastleigh

Following the Populus/Times Eastleigh poll that showed the Liberal Democrats five points ahead, there is a new Survation poll of Eastleigh in the Mail on Sunday tomorrow that shows the opposite picture, with the Conservative party four points ahead. Their topline voting intentions for Eastleigh are CON 33%(nc), LAB 13%(nc), LDEM 29%(-7), UKIP 21%(+5) - changes are from the previous Survation poll of Eastleigh a fortnight ago.

Both polls were conducted on the telephone and while I haven't seen the Survation tables both companies tend to use a similar methodology in terms of weighting and reallocating don't knows to the parties they supported at the last election. I understand they were carried out at about the same time, so it shouldn't be a "Rennard effect". The two polls show UKIP with the same level of support, and no significant difference in Labour support - the only difference is the figures for the Conservatives and Liberal Democrats.

I'll have a proper look when the Survation tables appear, but at first glance the most likely explanation for the difference between the two polls is just the normal variation within the margin of error... suggesting that the race really could be neck-and-neck.

I don't know if there are any polls of Eastleigh to come - I've heard rumours of a poll in the field over this weekend, but we shall see.

UPDATE: The tables for the Survation poll are up here. There are some minor differences in approach (Survation reallocated don't knows at a lower rate, and didn't weight up people who didn't vote in 2010 to as a high a proportion of the sample as Populus did), but none that would explain the difference. Not that the difference really needs a fancy explanation - once you take into account the high level of don't knows the difference between the two polls can easily be explained by normal margin of error.