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

Ahead of the first ever televised leaders' debate, the latest daily YouGov survey for the Sun put the Tories down four points to 37 per cent, with Labour down one to 31 per cent and the Liberal Democrats up four to 22 per cent. If repeated at the election on a uniform swing, the latest figures would leave Gordon Brown 45 seats short of a majority.