Boris wins London influentials' backing with 6 per cent poll lead

The Tory is on 44 per cent, with Ken Livingstone on 38 per cent and Liberal Democrat candidate Brian Paddick third on 12 per cent.

But Mr Paddick, the former Met deputy assistant commissioner, was well ahead when respondents were asked who would win their second preference votes - backing his belief that he can seize power if he makes it through to the second round of voting on 1 May.

Today's YouGovStone poll for the Evening Standard asked 533 Londoners drawn from the business, culture, education, government, media and voluntary sectors for their views on a range of questions on the Mayoral race.

According to the poll, Mr Johnson would attract 44 per cent of first preference votes, Mr Livingstone 38 per cent, Mr Paddick 12 per cent and Green candidate Sian Berry four per cent. After the initial vote count, the top two candidates will go on to the second round, with second preference votes of the eliminated candidates being re-allocated if they are for either of the two front runners. Mr Paddick was the most popular second choice, with 37 per cent of respondents prepared to offer him their second vote, followed by Ms Berry on 28 per cent, Mr Livingstone on 18 per cent and Mr Johnson on a poor 10 per cent.

If the first and second preference votes were added together, Mr Livingstone would receive 56 per cent and MrJohnson 54 per cent. However, not all second preference votes will come into play - if a voter's first choice makes it through to the second round their second preference vote is not counted.

Mr Paddick said today: "The way the voting system works means that only two people stand a chance of winning this election: Ken or me.

"Every Mayoral election to date has been decided by second preference votes. If it's Ken and Boris in the run-off, Ken will win. If it's Ken and me, I will win. If you've had enough of Livingstone you have to vote Paddick on 1 May."

Mr Livingstone scored well on his performance in his eight years as Mayor - 61 per cent felt he had done "very well" or "fairly well" while 39 per cent said he had done fairly or very badly. Mr Johnson was just one point ahead (on 36 per cent) when respondents were asked who would do most to enhance London's reputation. Mr Paddick got 11 per cent.

Mr Livingstone was most trusted to act in the interests of London in the event of another terrorist attack, beating Mr Johnson by 36 per cent to 28 per cent. Mr Paddick, who was one of the public faces of the Met after the July 2005 attacks, came third on 20 per cent. The Mayor was also judged best placed - by some distance - to improve the lives of London's ethnic minority communities, receiving 47 per cent backing. Transport was considered the priority issue by 34 per cent, followed by crime ( 28 per cent). The environmentand housing scored only five per cent and four per cent respectively.

Some 45 per cent of respondents said the congestion charge was very or fairly important in determining who they would vote for, while 54 per cent said it was not very or at all important.

A spokesman for Ken Livingstone said: "It is impossible to provide any serious comment on [the poll's] contents given that by its own admission the sample in this poll is not representative and must not be represented as such."

In the latest of our agenda-setting debates about issues facing London, the Evening Standard Influentials/ YouGovStone Debate tonight asks: What does London need from the next Mayor?

Guest speakers are Mr Johnson, writer Yasmin Alibhai-Brown, columnist Nick Cohen, former New Nation editor Michael Eboda and Sir Simon Jenkins. The debate, from 6.30pm at Cadogan Hall, Sloane Terrace SW1, is chaired by Evening Standard executive editor Anne McElvoy. Some tickets will be available on the door.