But there are others who hope to stop Boris, of course. George Osborne has built a formidable operation with an impressive team of advisers ready to help him launch a bid if the conditions seem favourable when Cameron does leave. This most political of Chancellors relishes "the game" and he has a deep knowledge of Westminster and Washington history. But although he enjoys a good plot, the Chancellor's friends says he is realistic about his prospects and public unpopularity. Unlike a figure such as Gordon Brown, who became consumed by the idea that he somehow had a divine right to be leader of his party and Prime Minister, Osborne is more pragmatic. If the cards fall in such a way as to make a bid feasible, he and his team will be ready. If not, he can position himself as the kingmaker and deploy his team in support of the likely winner, thus earning their gratitude and patronage.

So flexible is the Osborne agenda that he and Boris have let it be known that over the summer their families socialised quite happily. The pair are friends, it was reported. Yet these are the same friends who were at odds when it emerged that Osborne, with the support of Michael Gove, had sworn to stop him ever becoming Tory leader. Gove himself continues to insist that he himself would never stand.

If Osborne himself is not in a position to beat Boris to the leadership, he will need a candidate who might be "the one" capable of doing it for him. Sajid Javid, the Culture Secretary, could be that man. The son of immigrants, he became a senior banker and is used to working hard and winning. However, the extent to which he is Osborne's creation, as is often claimed, is overstated. Javid is not in politics to be anyone's puppet. He is determined to become Tory leader and point his party back towards social mobility, a message that could appeal to new voters if it comes from a source with personal experience of such subjects. Against that, he is largely unknown and he suffers a charisma deficit compared to Boris.

Both David Davis and Liam Fox, as representatives of the Tory Right, may run again, particularly if experience is at a premium in the aftermath of a Tory defeat and hung parliament. And the much younger Elizabeth Truss, the Environment Secretary, is pondering standing. Although her speech at the party's conference was not a success, with the section on cheese production (really) singled out for criticism, she is talented and has time to improve her presentational skills in the next few years. Before Margaret Thatcher became Prime Minister she too was mocked for a certain stiffness of manner.

The reader will notice that so far I have made only passing mention of ideas or policies when assessing the candidates. This is not accidental. While Javid and Truss are both believers in the need for an overhaul of British Conservatism to appeal to aspirational voters, and Davis and Fox have track records that suggest they believe in something similar, the battle for the leadership is not being conducted on the field of ideas. Neither of the interesting and emerging Conservatives who are most unashamedly intellectual — the Burkean philosopher Jesse Norman and the historian Kwasi Kwarteng — are yet quoted by their colleagues as contenders.

Instead, the race is about old-fashioned notions of raw power and the Tory tribe's search for a winning proposition in difficult circumstances. The potential appeal of Boris, according to supporters, is that he can transcend doctrinal debates and appeal to non-Tories tired of indistinguishable modern leaders. The case for Boris thus rests on his lively personality and restless good humour.