The media has been full of reports that Boris Johnson will soon announce his decision to return to the House of Commons. Few people will be surprised and most will be glad to see an end of the constant speculation. I suspect the decision will be made public a long time before the party conference. Both the Mayor’s Office and Number 10 want the issue to be settled sooner rather than later.

One senior Cabinet minister told me that this saga must not distract from key election messages and given that the party conference will mark the launch of the serious phase of the election campaign, Boris should ideally have been nominated for a seat by then.

Events have moved fast in recent weeks because Number 10 made it so very clear that Boris was wanted back in the Commons. That made things much easier for the former MP for Henley. No longer would he risk looking like he was returning to Westminster to destabilise David Cameron. Mr Cameron has not just opened the door to his return, he’s rolled out the red carpet.

My understanding is that the Tory leadership certainly want one of the country’s most popular politicians on the campaign trail but, more than that, having another big beast on the ticket adds to what will be a key Conservative theme: the echoing of an old Tory slogan – The Right Team For Britain’s Future. Observers often note that Tory strategists want to present the next election as a gladiatorial contest between David Cameron and Ed Miliband. There will be a significant element of that but political research also shows that in tough economic times it’s the strength and experience in depth that impresses voters.

In Tuesday’s joint Cameron-Osborne press event we saw the beginnings of this big-beasts-for-big-times strategy. Expect to see a lot more of Theresa May, Boris Johnson, Iain Duncan Smith and William Hague being contrasted with Ed Miliband, Ed Balls and, er, um, other household names on the Labour benches.

It’s a variation on the “don’t hand the keys back to the people who drove the car into the ditch” thesis. Voters suspect Miliband and Balls’s fingerprints are all over the steering wheel of the last Labour government but for most voters 90 per cent of Labour’s manifesto and personnel are unknown quantities. Do you want the country run by people you do not know, who have not told you what their policies are?

If Cameron wins re-election (and my hunch is that’s a 50/50 possibility) Boris will probably be invited to have a big job – ideally something like the B.I.S.C.U.I.T.S. job promoted by Paul Goodman. Tory MPs will then get to see whether they think he is capable of being as good a minister as he is a vote getter. Some Machiavellians not so far from Number 11 think he might not be.

If, alternatively, Cameron loses the election Boris Johnson will be in parliament and in pole position for the inevitable leadership race. It could be the messiest Tory leadership race we’ve ever seen if no candidate emerges who can both Unite the Right (there’ll be a huge demand to make peace with UKIP’s voters) and also keep the party focused on the NHS, housing and other voters of concern to swing voters. Boris will undoubtedly see himself as that unity candidate. If he can satisfy Londoners that in returning to parliament he hasn’t walked out on them (I think he does that by campaigning for laws that give his successor more powers) it could be interesting.