Steven Norris: "This confirms what I have been saying"

The denial comes after the BBC quoted Tory sources as saying that focus groups commissioned by the party had found the millionaire novelist was one of the main reasons why the voters still see the Conservatives as the party of sleaze.

Tory leader William Hague and party chairman Michael Ancram have issued a joint statement rejecting the reports.

They said: "Neither William Hague nor I have ever received a report from any of our focus groups which refer to Jeffrey Archer or his candidature for mayor of London.

"Nick Sparrow, of ICM, who conducts our focus groups, confirms this is the case."

The statement comes as the BBC has learned from Tory sources that there is concern in the party that Lord Archer's poor public image could "tarnish the whole party" if he beats Steven Norris when the result of the membership ballot for the nomination is announced on Friday.

Norris attacks

Lord Archer's rival has seized on the news, claiming he is the only candidate who could deliver a victory for the Tories in next May's mayoral elections.

Steve Norris says only he can win London for the Tories

Mr Norris said the party research and another private poll commissioned by Lord Archer merely confirmed what he had been saying throughout his campaign.

"If Conservatives want a chance of actually winning they have got to have a candidate that appeals across the party divide and it's pretty clear that that isn't going to be Jeffrey in any event," he said.

The former minister added: "The evidence has been staring us in the face because Jeffery Archer paid for some very expensive MORI [polls] that already proved that he couldn't get more than the rank core Conservative vote.

"From my point of view, it's nice to have some independent verification of that but it's hardly news."

But Labour mayoral hopeful Ken Livingstone defended Lord Archer.

He said the Tory peer was "most formidable and effective candidate I have ever seen".

Questions of character

Media commentators have made much of questions about Lord Archer's past during the race for the Tory nomination.

In 1987 it was revealed that he had sent a messenger to give a prostitute £2,000 at King's Cross station in London.

A jury later awarded Lord Archer £500,000 in libel damages after it accepted he had never slept with the woman.

Then in 1994 questions were raised about Lord Archer's dealings in Anglia Television shares. Lord Archer denied claims of insider dealing but accepted he had made serious errors of judgement.

In his battle to be mayor Lord Archer has tried to confront the doubts over his suitability