How Cameron could avoid throwing his party into chaos if he wins in May
Cameron's remarks to the BBC's James Landale prompted a flurry of activity, with commentators accusing the PM of appearing arrogant and preempting May's vote. Whether it will have electoral consequences is yet to be seen, but his statement is much more likely to have been aimed at his own party than the public at large - in effect, promising to reward party loyalty with a shot at the leadership in the next parliament.
Yet it poses an interesting question - how does a sitting PM formally nominate a successor without having to stand down?
There is a possible loophole that Cameron could employ in order to meet his commitment but avoid throwing the party into chaos during an election. That is, splitting the roles of Prime Minister and party leader.
It's happened before. Back in May 1940 then-prime minister Neville Chamberlain faced a no confidence vote in a hostile parliament following the disastrous Norwegian campaign, where allied forces were forced into an embarrassing retreat by German troops with Britain losing two destroyers and the aircraft carrier Glorious in the process.
During his speech in the Commons, Chamberlain was heckled by Labour MPs accusing the government of having "missed the bus." Although the government won the day by 281 votes to 200, a backbench rebellion left it looking shaky and on May 10, Chamberlain resigned in favour of fellow Conservative Winston Churchill.
The pertinent point here is that when Chamberlain resigned as Prime Minister in May, Churchill did not become leader of the Conservative party until October. For the better part of six months the roles were distinct.
Given Cameron's stated intention not to stand again in 2020, if he wins in May he could easily accomplish an orderly transition by holding Conservative party leadership elections well ahead of the public vote. That way a new leader would have time to establish themselves as the party's candidate both within the party and to the wider public without necessarily having to threaten or undermine the prime minister's position.
Of course, many will still argue that such a system would still leave Cameron as a lame duck in office. That's possible - especially if the eurosceptic wing of the party manage to secure an ally as party leader - but it is by no means a necessary outcome of such an arrangement.
It would be much more likely that leaving succession plans open would give rise to instability and division as competing factions vie for influence, which would be a major problem with a narrow majority government looking the best that the Tories can hope for at this stage. Having experienced one of the most rebellious parliaments on record, Cameron will be desperate to avoid a repeat performance.