If not Dave, then who? The parlour game that might get serious

It is horrible to imagine. It would be a tragedy, for party and country. Even contemplating it seems lurid and, given recent events, deeply mischievous. It is certainly not something for loyal Tories to discuss in public. But, in their darker moments, few Conservative politicians will have not asked themselves the question in the past turbulent week: if David Cameron were to be run over by a bus tomorrow, who would lead the Conservative party?
At Westminster, it is amazing how quickly today’s parlour game can become tomorrow’s leadership battle. For those who prepare properly (as the Blairites did in 1994) the rewards can be immense. In Mr Cameron’s case, what is striking is the fact that there is leadership speculation at all. After the triumph of the May local elections, the Tories seemed likely to be the single largest party in the next parliament. Now, after Labour’s resurgence in the polls and the Tories’ shambolic performance in the Ealing by-election, a very different prospect lies ahead of Tory MPs as they depart for the summer recess: a spring general election and the ignominy of a fourth successive defeat.