Boris Johnson was tonight hoping to pull off a dramatic election victory to become the new Mayor of London.

The final outcome is still not yet known and the result is expected to rely on second choice ballots, but Ken Livingstone's campaign manager Tessa Jowell admitted before midnight she did not think the veteran leftwinger would hold sway.

She said: "I think it's highly unlikely that Ken will be mayor of London after the end of this evening."

In another interview, she said: "We don't quite know the result yet, but we fear that Ken has lost."

However, Ms Jowell tried to sound upbeat, adding: "If you look at Labour's vote in the assembly there are some unexpected surprises there that demonstrate the loyalty of the Labour vote".

Asked if he was encouraged by the Conservatives' performance elsewhere, Mr Johnson replied: "I think the party's done fantastically nationally but London is a very different kettle of fish and we'll have to see what happens."

Meanwhile, Mr Livingstone told reporters he was "feeling fine". About 2.4 million Londoners, 45 per cent of the electorate, took part in the election - the highest ever turnout for a mayoral poll since the post was created in 2000.

Following his selection as the party's candidate last September, Henley MP Mr Johnson was at the head of a well-organised, and well-funded, seven-month Tory campaign.

It is understood he benefited from a high turnout in the outer boroughs surrounding Labour's inner-city strongholds, following what his strategists dubbed the "doughnut strategy".

Opinion polls had placed Mr Livingstone and Mr Johnson neck-and-neck, with Lib Dem ex-police commander Brian Paddick a distant third.

The final result was delayed several times - partly due to the increased turnout.