BORIS Johnson has rulled himself out of the race to become leader of the Conservative Party.

The former London mayor's decision not to join the battle leaves Home Secretary Theresa May as hot favourite to succeed David Cameron as the next Prime Minister.

It came after the shock announcement by fellow Brexit campaigner Michael Gove - who was widely expected to be Mr Johnson's running mate - that he was putting himself forward for the leadership.

In a dramatic press conference just moments before the deadline for nominations passed, Mr Johnson said that the next Tory leader would have to unify his party and ensure that Britain stood tall in the world.

And he said: "Having consulted colleagues and in view of the circumstances in Parliament, I have concluded that person cannot be me."

Mr Johnson was one of the most high profile figures involved in the Brexit campaign and many acknowledge that his presence was one of the crucial factors in persuading many wavering voters to opt to leave the EU.

  • Here is a brief guide to the five Conservatives who will be standing for party leader.

Theresa May

The Northern Echo:

A quiet Remain backer who is seen as a steady hand to calm the party after its post-Brexit turbulence. The current Home Secretary's campaign will be run by Chris Grayling. The Maidenhead MP is seen as the favourite to succeed Mr Cameron.

She said: "My pitch is very simple. I'm Theresa May and I think I'm the best person to be prime minister of this country."

Michael Gove

The Northern Echo: Education Secretary Michael Gove

The Justice Secretary, who sparked controversy when he was handling the education brief, was at Mr Johnson's side for much of the Vote Leave campaign.

Mr Gove appeared to be throwing his support behind Mr Johnson's leadership ambitions, before performing an incredible about-turn and running himself, saying he did not believe Mr Johnson could "provide the leadership" the Tories needed. Only a three hours after the Gove statement Mr Johnson quit the contest.

Stephen Crabb

The Northern Echo:

The Work and Pensions Secretary is hugely popular in the Conservative parliamentary party and comes from the sort of ordinary background that chimes with many voters.

The former Welsh Secretary says the party should be led by someone ''who understands the enormity of the situation we're in and who has got a clear plan to deliver on the expectations of the 17 million people who voted to come out last week'' including keeping the United Kingdom together.

Andrea Leadsom

The Northern Echo:

An assured performance by the Energy Minister for the Brexit side in the referendum campaign won Ms Leadsom praise.

The former banker and fund manager announced she was in the running, tweeting: "Let's make the most of the Brexit opportunities!"

Liam Fox

The Northern Echo:

Mr Fox - who unsuccessfully sought the top job in 2005 - was the first to confirm he was considering a fresh bid. An outspoken supporter of Brexit, he would hope win over the right of the party.

The former defence secretary resigned from the front benches in 2011 after allowing his friend and best man Adam Werritty to take on an unofficial and undeclared role as his adviser.