Boris Johnson will be given a Cabinet position once he stands down as Mayor of London, David Cameron has said.

The Prime Minister has also insisted he will serve a five year term in Downing Street following claims he would hand over the reins to his successor in 2019.

Mr Cameron's decision to reveal before the general election that he would not fight a third term has prompted frenzied speculation about the runners and riders lining up to take the top job.

Chancellor George Osborne and Mr Johnson along with Home Secretary Theresa May were all identified by the Prime Minister as leadership candidates.

Education Secretary Nicky Morgan has also thrown her hat in the ring.

Asked about the contenders jockeying to replace him, Mr Cameron told the BBC: "I'm very proud that I run a team and a team with some real stars.

"We are seeing this week great speeches by Boris Johnson - we've just heard a vision for how we bring our country together - a great speech by Theresa May, one of the architects of modernisation of the Conservative Party, a brilliant speech by George Osborne about changing the way we run our country.

"It demonstrates the Conservative Party is a team of leaders, not simply one person, a team that's got great ideas and visions for the future, so I couldn't be happier."

The Prime Minister said he was "looking forward" to bringing Mr Johnson into No 10, insisting he wants "big figures" in his team.

He said: "I want to have the big figures in my team. That's why I'm looking forward to Boris finishing his time as Mayor and coming into my team in Number 10.

"We've got stars, we've got people with real stature and great ideas for the future of this country."

Asked if Mr Johnson, who currently attends political Cabinet, will get a ministerial job: "Definitely. We will have to see which one, but definitely."

Downing Street sources later confirmed that the PM intended to hand the mayor a Cabinet level job.

Mr Cameron underlined his plans to remain in post until 2020 and insisted he was "going to give it everything I've got".

He told Channel 4 News: "I'm looking forward to the next five years. I feel I'm halfway through the most important job of my life and I'm going to give it everything I've got." Asked if that meant serving all five years?, he replied: "Oh yeah."