Boris Johnson's general election bid puts him at centre of leadership scrum

Boris Johnson, in a typical faux-naïf Borrism, said once of his leadership ambitions that he might "pick up the ball if it came loose from the back of the scrum". Wednesday morning, he managed to position himself perfectly as scrum-half in a prime position.

He not only announced he intends to stand for election as an MP in 2015, and remain London mayor for the remainder of his term, but he presented himself as a pragmatic Eurosceptic, willing to seek reform in Europe but convinced there is nothing for Britain to fear about leaving the EU but fear itself.

That positions him perfectly with the Tory grassroots if a sudden party leadership election is called after the next election. If the greasy ball does squeeze out from the scrum, others including Theresa May and George Osborne may try to grab it off him, but in the event of a defeat it is likely the constituency parties will flock to Johnson as the proven vote-winner that somehow transcends politics. He would be the postmoderniser that moves the story on from Cameron's modernisation, even if he might not find the grind as opposition leader an unalloyed joy.

Osborne, in such a speedy contest, would probably be stymied as the continuity candidate. His only serious chance is if the Conservatives win on the economy in 2015 and Cameron then stands down in 2018 after the EU referendum, completing 13 years as party leader.

It has been written that on hearing Johnson's news, Cameron would be staring morosely at a pile of rotting fish on his holiday retreat in Portugal, but it is just as likely he will have a sense of relief. He may have lost Sayeeda Warsi, but Johnson is a star player and can take a bigger role in the election campaign as an MP. Cameron has long decided to embrace Johnson, rejecting the advice of those aides that say he is fundamentally untrustworthy. Unsurprisingly, Cameron was quick to welcome the news on Twitter, now the chief mode of political communication – at least in recess. He had no other option, and the Conservative conference will now include a great rally to welcome Johnson back to the parliamentary fold.

It also avoids months of further speculation, and brings to an end the frankly tiresome and narcissistic indecision that Johnson has a tendency to display.

He had a practical need to make the decision this week before he goes on holiday. His friends admit that if he is to remain London mayor, he needs a seat in London. He wants to go through the full selection process without any special privileges, and the safe seat of Uxbridge and South Ruislip will be selecting this month. Although his last period in parliament was worse than undistinguished, he himself promises he has developed a new seriousness in the past year and is ready to cast off the role of Prince Hal. A more stable family life is said to have contributed.

His friends also say that if he is an MP in 2015 and Cameron is elected he will not be seeking a ministerial berth at least until his term ends in 2016. Instead, he would use his base in parliament to secure his London legacy lobbying for Crossrail 2, a transfer of tax powers to Britain's cities and the protection of the City's interests in Europe.

It is also significant that he used a speech clarifying his views on all things European as his launchpad for a return to the Commons. There has been endless speculation about whether Johnson is in truth a Europhile, or whether his once sound scepticism has been turned by all the rich London businessmen and financiers he meets in his mayoral role.

His speech set out a clear and highly ambitious EU reform agenda, and unlike Cameron, he said that he is quite prepared to contemplate life outside the EU, arguing that the 2017 referendum can be about exit.

In reality, the report he commissioned from his chief economist on Britain outside Europe and the supposed basis for his speech makes the case for staying in a reformed Europe. It is also highly critical of the government's approach to its European partners including the damning assessment "even though we fully accept that there is an economic case for leaving, one has to ask why the UK does not try and play a bigger leadership role in the EU. It seems less engaged than others, more passive than active, consequently not safeguarding the interests of its key economic sectors".

There is one problem. Boris made a solemn promise during the 2012 mayoral election, telling the Evening Standard: "If I am fortunate enough to win I will need four years to deliver what I have promised. And having put trust at the heart of this election, I would serve out that term in full … I made a solemn vow to Londoners to lead them out of recession, bring down crime and deliver the growth, investment and jobs that this city so desperately needs. Keeping that promise cannot be combined with any other political capacity."

On Wednesday it seemed necessary to read the small print of that solemn promise. It no longer applied once London was out of recession. The clearly broken promise burns some of the gloss off Johnson – but that still leaves a lot of gloss.

Powered by article was written by Patrick Wintour, political editor, for The Guardian on Wednesday 6th August 2014 20.36 Europe/London © Guardian News and Media Limited 2010