Tories 'trail Labour in must-win seats'

The Ipsos Mori survey for Thomson Reuters provided further evidence that a hung parliament was on the cards at the general election.

It found that in constituencies set to determine the outcome of the election, Labour leads the Tories by four points among those certain to vote.

The poll was taken in 56 Labour-held seats that the Tories need a swing of between five and nine per cent to win.

David Cameron needs a national swing of about seven per cent towards the Tories to get a majority of MPs and form the next government.