David Cameron's decision to campaign on traditional Tory issues appears to have boosted his party's ratings, according to the latest "poll of polls" for The Independent.
A marked difference emerged between the surveys conducted at the end of July and start of August, when Labour averaged 39 per cent and the Tories 33 per cent, and those taken at the end of last month after Mr Cameron raised issues such as immigration, tax, Europe and crime. By then, Labour was on 38 per cent, the Tories 36 per cent and the Liberal Democrats unchanged on 16 per cent.
Overall, Labour still enjoyed a five-point advantage on a weighted average of the August polls by Ipsos MORI, Populus, YouGov, ICM and ComRes – enough to give Gordon Brown an increased majority of 100 at a general election.
But Tory strategists will take some comfort from closing the gap in the past two weeks. They suspect this will deter Mr Brown from calling an autumn election.
Labour officials believe Mr Cameron will pay a long-term price for returning to traditional Tory themes, saying it backs Labour's claim that the Tories are "lurching to the right."
John Curtice, professor of politics at Strathclyde University, who compiled the figures, said they showed that the "Brown bounce" after Tony Blair stood down in June was not a "short-term aberration". However, nearly all of Labour's gains happened shortly after the handover. He said Mr Cameron's personal popularity had taken a nosedive this summer, with half the public thinking he is doing a bad job.
Labour would still retain power on the basis of the most recent polls, but its majority would be cut to 54. "If Mr Brown simply wants his own mandate, he might want to call an election now," said Professor Curtice. "But if he wants to increase his own party's majority, then the most recent polls suggest he might not secure his objective."
There is no cheer for the Liberal Democrats. Their ratings are as low as any time since the last election and are back to where they were when Charles Ken-nedy was ousted as leader.
"The pressure on Sir Menzies Campbell seems bound to grow unless the gradual erosion of the party's support is halted," said Professor Curtice.
The drop in Liberal Democrat support could make an autumn election a safer option for Mr Brown, he said, since it means that the danger of Labour losing its overall majority has receded significantly.
With the third party on the 23 per cent share of the vote it won in 2005, the Tories need only be just ahead of Labour to deny it an overall majority. But when the Liberal Democrats are on 16 per cent, the Tories must be at least three points ahead of Labour to achieve a hung parliament as Labour recaptures some of the seats it lost in 2005.