When should Boris seek to return to the Commons? May 2015 looks most sensible.

By Tim Montgomerie
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Exactly one week ago Boris Johnson had his interview with Eddie Mair. It looked bad at the time but one day later the Michael Cockerell documentary showed Boris at his best. Accusation after accusation was thrown at London's Mayor in the one hour BBC2 programme but the post-match consensus was that he had emerged at least unscathed and probably enhanced. His larger-than-life personality helps him overcome nearly all criticisms.

Those inside Number 10 who had enjoyed Boris Johnson's Night-Mair interview were no longer smiling by Thursday. A YouGov poll showed that Boris would eliminate Labour's opinion poll if he became leader. Boris was particularly popular among the UKIP voters who have deserted David Cameron.

On yesterday's ConHome I warned against ousting Cameron before the next election. Although I think Boris would be a better electoral proposition than Cameron we are not starting with a blank piece of paper. We are in Coalition with the Liberal Democrats. Cameron would not surrender meekly to Boris. Any leadership election would be bloody. If Cameron was no-confidenced other MPs - including, I suspect, the likes of Graham Brady and Theresa May - might stand too. The party infighting in the middle of difficult economic times would repel many floating voters. Boris could make this case for going back to parliament early but many Londoners would feel he'd broken a promise to serve them until 2016.

For Matthew d'Ancona in The Sunday Telegraph Boris would be wrong to stand before 2015 but hints that standing in May 2015 would be a real possibility:

"It is less than a year since the Mayor was re-elected. For him to seek a Commons seat in the next winnable by-election would be ill-received by Londoners, and hard to explain except as a preparation for treachery. But to put himself forward for a seat in the 2015 general election would be a different matter entirely. Boris could argue quite reasonably that he hoped to assist his party on the national stage when his second term expires in 2016. Yes, he would be performing two roles – Mayor and constituency MP – for a year. But there is recent precedent in Ken Livingstone, who served as Mayor and as MP for Brent East for just over a year before the 2001 general election."

Matt d'Ancona says that if Cameron wins the next election it might be one of the next generation of Tory MPs who will succeed him - in roughly 2020. If this logic is correct Boris' best chance would appear to come in 2015 but is Boris suited to being Leader of the Opposition?

A fantasy 2020 Cabinet

For me the Tory Party has two huge assets - Boris and the Class of 2010. Combining them - Boris' electability and the modernised Thatcherism of the 2010 intake - seems the most attractive project if Cameron cannot keep his premiership on the road. Matt d'Ancona is probably right therefore. Boris should stand in 2015.