Today’s batch of marginal snapshots includes three of the most intriguing and closely contested seats of this general election campaign.

South Swindon is a very tight Conservative-Labour marginal which I have polled twice before, finding a tie both times. My latest survey, completed yesterday, found the Tories with a one-point lead – a statistically insignificant movement that leaves the seat too close to call.

In Thanet South I found the Conservatives two points ahead of UKIP, 34 per cent to 32 per cent, despite nearly nine out of ten voters there saying they have had campaign contact from the challengers. In my recent polls in the constituency I have found the Labour share drifting down as the Tory share edges up, suggesting that Labour supporters may be lending their vote to the Conservatives to stop Nigel Farage. However, the lead remains well within the margin of error and the seat could still go either way.

Labour’s lead in Sheffield Hallam is down to a single point, compared to two in March and three in November. While 30 per cent of 2010 Liberal Democrats in the seat say they intend to vote Labour next week, 31 per cent of 2010 Conservatives say they will now vote Lib Dem. Tory voters in the seat were also notably less likely than they are elsewhere to say that they rule out voting for Nick Clegg’s party. Their decisions could have more impact than most in determining the shape of the next government.

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