The plotters have him in their sights: A vote of no confidence must take place if 46 Tory MPs demand it. Can David Cameron survive?

Men have long met behind closed doors to decide who should be the leader of their great movement. Is there someone available who can appeal both to traditionalists and the supposed centre-ground of opinion? Should they opt for youth or experience? As these questions are debated, new alliances are forged, old friendships are betrayed, murky deals are done, until a winner emerges who can be paraded in front of the faithful. Cardinals do something similar when they are choosing a new Pope. But when it comes to intrigue and infighting the Conservative party can rival the Catholic Church.

Tories wonder if it will soon be time for them to pick their own new leader. The subject dominated a recent private dinner of the No Turning Back Group and other discussions when Conservative MPs meet to eat and plot. After all, for Tory leaders retirement before death is hardly unprecedented. Of David Cameron's six predecessors, three have been brutally thrown out. To memorise the roll-call of slaughter an equivalent is required of the mantra learnt down the generations about the six poor wives of Henry VIII. That ran as follows: "Divorced, beheaded, died; divorced, beheaded, survived." In the case of the Tories since the mid-1960s it has been Ted Heath (removed), Margaret Thatcher (removed), John Major (almost removed), William Hague (death by baseball cap), Iain Duncan Smith (removed) and Michael Howard (survived). Cameron survives, for now. 

In one sense, the recent speculation about the future of the Prime Minister's leadership is mad. He starts with several significant advantages. Even though the Labour party has an opinion poll lead in the region of ten to 12 points, it is much smaller than might be expected at mid-term when the economy is flat-lining and the country is in a funk. The opposition knows this and is not particularly confident of victory, even though the coalition government is struggling. Then there is the Ed Miliband question. For all that I have long argued that he is both underestimated and steelier than he seems, Miliband is a very left-wing Labour leader who has not yet made the connection required with sufficient numbers of voters. This was apparent in the Eastleigh by-election. An opposition on the verge of government should have been able to make at least some impression and attract disgruntled voters, yet Labour did not. It came a miserable fourth.

As Cameron likes to point out, Miliband also remains dogged by basic questions on the economy. The answers the party has are transparently hare-brained and inadequate. Even if the government and Chancellor George Osborne are seen to be failing, Labour is going to struggle to convince voters that its plans are any better. Britain has been running enormous deficits for five years now, and almost a trillion has been added to the national debt. Will a touch more really be the match that magically relights the economy? For good reason, Labour frontbenchers look shifty when they are asked how much extra they would spend and borrow in government. They simply do not know.