British Prime Minister David Cameron says he will serve a full second term if he's re-elected in May — but he won't seek a third.

Cameron told the BBC Monday that it would be "time for new leadership" after a second five-year stint.

He joked that "terms are like Shredded Wheat: two are wonderful but three might just be too many."

Cameron's predecessor, Tony Blair, governed for 10 years, stepping down midway through his third term.

Cameron has been prime minister since 2010 as the head of a Conservative-Liberal Democrat coalition government. His Conservatives hope to win a majority on May 7, but polls suggest another coalition is the most likely outcome.

Cameron named Home Secretary Theresa May, Treasury chief George Osborne and London Mayor Boris Johnson as possible successors.