Ashcroft poll of ultra-marginals

Lord Ashcroft has released a second tranche of polls in Con-v-Lab ultramarginals, full details are here. It's a repeat of his first polling of Con-Lab seats in April and now as then, Ashcroft polled the 12 most marginal Conservative held seats with Labour in second place, plus two other seats (South Thanet and Great Yarmouth) that he thought might have interesting UKIP results. Note that this wasn't what we've often called a "marginal poll" in the past (a single poll of a group of marginal seats), it was 14 separate polls, one in each seat, individually sampled and weighted.

In April, the average swing in the 12 Con-Lab ultra marginals was 5.5% from Con to Lab, the same as in the national polls at the time. In other words, Con-Lab ultra-marginals were behaving right in line with national polling.

The average picture in the national polls is unchanged since April - the national swing from Con to Lab in GB polls conducted during the time Ashcroft did his latest fieldwork was 5.4% from Con to Lab. Lord Ashcroft's findings in the marginal polls however have shown a slight weakening in the Labour position relative to the Conservatives, looking at just the 12 ultra-marginal seats the Conservatives are down by about 1.5% on average, Labour down by about 2.7%, UKIP up by about 4.5%. This looks like a European boost - the previous poll was done before the European election campaign, this one started in mid-June. The average swing in the ultra-marginals is now 4.9 from Con to Lab, meaning an increase in UKIP support has slightly hurt Labour. While the difference is too small to really make a fuss about, it also means that Ashcroft's polls now show a slightly smaller swing in Con held marginals than nationally - in line with what we'd expect given the normal incumbency effect.

In two of the seats polled, Thanet South and Thurrock, UKIP were ahead in voting intentions, which will be enormous help for them in convincing voters they are a viable general election vote in the local area.