Ken extends his lead

Ken Livingstone has stretched his lead in the mayoral race to 14 per cent, an Evening Standard poll reveals today.

The Mayor, with 41 per cent, is now well ahead of chief rival Steve Norris on 27 per cent and looks set to win another four years at City Hall.

At the end of the first fortnight of campaigning, Mr Livingstone has managed a small one-point increase in support, up from 40 per cent. But Conservative candidate Mr Norris has slipped backwards by four points from a previous high of 31 per cent, according to the YouGov survey.

His lost supporters appear to have defected to boxing promoter Frank Maloney of the anti-Europe United Kingdom Independence Party, who has jumped four points to six per cent.

Simon Hughes, the Liberal Democrat, is marooned on 17 per cent, the same standing as in the previous Evening Standard poll two weeks ago.

The figures point even more closely to a two-horse race between Mr Livingstone and Mr Norris on 10 June. Among the poll's other findings:

Conservatives have opened a sixpoint lead in the battle for the London Assembly, mainly because of a fall in Labour support.

The threat of the extremist British National Party winning an assembly seat has receded.

The Greens and UKIP have both increased support in the assembly contest but the Lib-Dems are slightly down.

The fall in Labour's support for the assembly, down from 33 per cent to 29 per cent, will set alarm bells ringing among Tony Blair's election strategists.

It suggests the party is haemorrhaging support in London after weeks of controversy over Iraq and Mr Blair's leadership - and that only Mr Livingstone's personal standing is saving him from being dragged down.

Mr Norris's fall, meanwhile, contrasts with his party doing well in the assembly. That will fuel speculation that the Norris campaign has been hamstrung by controversy over his job with rail maintenance firm Jarvis.

Although Mr Norris is understood to have discussed resigning from Jarvis with his advisers, his view is that it is not an issue on the doorstep and quitting now would look "weak".

But previous surveys for the Evening Standard have shown Londoners think he should stand down by a two-to-one majority.

The survey shows that Mr Norris is more popular with women than men. And he is ahead of Mr Livingstone among the over-fifties, a factor which could help even the score because older people say they are more likely to bother voting.

Mr Livingstone is slightly more popular with men than women and has a massive two-to-one lead among the under-thirties. The Lib-Dems will be deeply disappointed by Mr Hughes's

failure to climb up the rankings. UKIP may have enjoyed a bounce from the decision by Robert Kilroy-Silk to stand as a Euro MP, while both they and the Greens have benefited from the exposure given to smaller parties during the campaign.

All the major parties will be relieved that the far-Right BNP appears to have stalled, falling from the crucial five per cent mark - which could mean winning an assembly seat - to only four per cent.