David Cameron has promised not to stand for a third term as prime minister, joking: "Terms are like Shredded Wheat. Two are wonderful, but three might just be too many."
Cameron named three colleagues as possible successors as Tory leader – Theresa May, George Osborne and Boris Johnson.
In an interview with BBC News, he was asked if he would go for a third term if he remained PM after the general election.
He replied: "No. I think I'm standing for a full second term.
"I'm not saying all prime ministers necessarily definitely go bad, or even go bad at the same rate, but I feel I've got more to bring to this job, the job is half done, the economy's turned round, the deficit is half down and I want to finish the job.
"I didn't just come to do this to, you know, deal with the debts and the mess, I want to go on with the education reforms and the welfare reforms.
"There definitely comes a time where a fresh pair of eyes and fresh leadership would be good, and the Conservative Party has got some great people coming up: the Theresa Mays, and the George Osbornes, and the Boris Johnsons.
"You know, there's plenty of talent there. I'm surrounded by very good people. The third term is not something I'm contemplating."
Cameron, who became prime minister in 2010, said it would be time for "new leadership" after 2020.
"Countries, like big organisations, benefit from strong and consistent leadership," he said. "But there comes a time when you want a fresh pair of eyes and a fresh agenda.
"Certain things... other people would bring, and so you must never think that you're indispensable. However mad you go in this job. I've said I'll stand for a full second term, but I think after that it will be time for new leadership."
Some political commentators said the move was a mistake, pointing to how Tony Blair's authority dwindled when he made a similar commitment.
I'm surprised Cameron's made the same mistake as Blair..A full term and no more. Blair lost authority from the moment he uttered the words.
Given his respect for Blair, did Cameron didn't not remember how difficult life got for The Master once he declared a time limit on his job?
That whoosh you just felt? Authority evaporating...
Labour branded Cameron "arrogant" for assuming voters would re-elect him.
Douglas Alexander, Labour's election strategy chief, said: "The Tories are taking the British public for granted.
"It is typically arrogant of David Cameron to presume a third Tory term in 2020 before the British public have been given the chance to have their say in this election. In the UK it is for the British people and not the Prime Minister to decide who stays in power."
And some eagle-eyed viewers spotted an interesting message near Cameron's kitchen window.
Is it just me or does Cameron have a sign saying "Calm Down Dear" behind his sink. Well, one of his sinks.
Does David Cameron have a red chopping board that says 'calm down dear' on it?
A lovely souvenir of this incident in 2011, perhaps.
