The Conservatives will still struggle to win a majority at the election, according to a new opinion poll which shows the party's lead over Labour falling to six points.

The latest daily YouGov survey for the Sun put the Tories down three points to 37 per cent, with Labour down one to 31 per cent and the Liberal Democrats up two to 20 per cent. If repeated at the election on a uniform swing, the latest figures would leave David Cameron 43 seats short of a majority in a hung parliament.

But the poll also found that voters believe the Conservatives performed best in the first week of the election campaign. Twenty five per cent of voters said the Toris had impressed the most, with the Liberal Democrats on 16 per cent and Labour on 13 per cent.