Boris Johnson 'to seek return to Commons in 2015'

Winning second term as London Mayor would not preclude standing in the next general election

Boris Johnson plans to seek a return to the Commons at the 2015 general election, a move which could see him emerge as the front-runner to succeed David Cameron as Conservative Party leader.

Mr Johnson's future prospects will receive a huge boost today if, as is expected, he sees off the challenge from Labour's Ken Livingstone and wins another four-year term as Mayor of London. Although Mr Johnson has denied that he will be a Tory candidate at the 2015 election and the London Evening Standard reported today that he has pledged to stay for a full four years if re-elected, close allies believe he will do so rather than look for a chance to return to Westminster in a by-election.

They insist he could serve as both an MP and London Mayor for 12 months before leaving City Hall in 2016 when his second term ends.

One senior Conservative told The Independent yesterday: "He could not wear two hats for a long period but doing it for 12 months would not cause a great controversy. Tory associations in London and the Home Counties would queue up to have him as their candidate. He would say he was representing London in Parliament for a year."

Tory MPs believe Mr Johnson would be in pole position to succeed Mr Cameron if he lost the 2015 election and resigned or retained power and stood down before the following election, as some allies of the Prime Minister expect.

One said: "Boris is seen on the Tory benches as a winner. He could be the only Tory to win an election since John Major in 1992. Cameron and Osborne didn't win in 2010. There is a growing view [among Tory MPs] that they don't really stand for anything. We know what Boris stands for – low tax, a Europe referendum, tough on law and order. He can communicate that and has charisma."

The final opinion poll of the London battle, by YouGov for the London Evening Standard, showed Mr Johnson on course for a 53-47 per cent over Mr Livingstone. It found that two in 10 Labour supporters intend to reject Mr Livingstone, with half planning to switch to his Tory opponent.

The Conservatives hope that the pain of heavy losses in yesterday's local elections will be reduced by a Johnson victory. Similarly, their Labour counterparts are worried that the party's expected gains in English and Welsh councils will be overshadowed by its failure to land the big London prize. Labour is likely to do much better in the London Assembly elections, which would allow it to blame a defeat in the mayoral poll on Mr Livingstone's personal unpopularity.

As the town hall polls closed last night, the Conservatives admitted they will not repeat their unexpected gains in council elections a year ago, when many of their traditional supporters turned out to vote "No" in the referendum on the voting system on the same day. Tory officials said they could lose 450 seats this time.

The Liberal Democrats acknowledged their local government base will be further eroded but hope that the losses will be lower than last year, when they lost more than 700 seats. A similar performance this year would see them lose just over 300 seats, so they are hoping to contain their losses to around 200.

Labour is certain to make hundreds of gains when the final local authority counts conclude this afternoon because the party did badly when the same seats were last contested in 2008. Labour officials hope for about 350 gains in England and 100 in Wales this time but academics say the party needs to gain between 600 and 700 to show it is on course to win the next general election.

A difficult set of elections for the two Coalition parties against a background of spending cuts and a flat-lining economy has been compounded by a series of unforced errors since the Budget.

The damage is revealed in The Independent's latest "poll of polls", which shows that the Conservatives' rating has dropped to its lowest level since the 2010 election. They are down three points on last month to 33 per cent, while Labour remains on 40 per cent and the Lib Dems are unchanged on 11 per cent. These figures would give Labour an overall majority of 56 if repeated at the next general election.