Labour are 19 points behind

The YouGov survey for The Sunday Times puts the Conservatives up one, on 46%, and Labour up two, on 27%.

It suggests the Government's economic recovery package this month has done little to improve Labour's chances of beating the Tories.

The £1 billion energy package announced by Prime Minister Gordon Brown came only while the poll was being undertaken.

The Liberal Democrats, gathering in Bournemouth for their annual conference, are down two points on 16%.

Some 73% of voters felt Mr Brown was doing a bad job as prime minister, compared with 20% who thought he was doing well.

That gave him a net negative rating of 53%, while Tory leader David Cameron had a net positive rating of 27%.

YouGov questioned a representative sample of 2,161 British voters online between September 10 and 12.