David Cameron has announced that he will step down as Prime Minister by October after the UK voted to leave the European Union.

An emotional Mr Cameron spoke outside Downing Street after the Remain campaign that he had fronted lost out in the crucial vote.

He said he felt there is now a need for fresh leadership and believes a new Prime Minister should be in place before the Conservative party conference in October.

He said: "The British people have voted to leave the European Union and their will must be respected.

“The will of the British people is an instruction that must be delivered."

His voice breaking, Mr Cameron said: "I love this country and I feel honoured to have served it and I will do everything I can in future to help this great country succeed."

"The country requires fresh leadership to take it in this direction,"

"I will do everything I can as Prime Minister to steady the ship over the coming weeks and months, but I don't think it would be right for me to try to be the captain that steers our country to its next destination."

LIVE BLOG: Reaction to the United Kingdom's decision to leave the European Union

He said he would leave it to his successor to invoke Article 50 of the Lisbon Treaty, which kicks off the two-year process of negotiating a new trade relationship with the UK's former partners.

His announcement will trigger a battle for the Conservative leadership - and the keys to Number 10 - likely to feature Brexit standard-bearer Boris Johnson taking on figures such as Home Secretary Theresa May, who took a low profile in the referendum campaign.

WHO ARE THE CONTENDERS TO REPLACE DAVID CAMERON?

David Cameron has announced he will stand down as Prime Minister by October.

Here we look at some of the potential contenders to replace him:

:: Boris Johnson

The former London mayor is the bookies' favourite to succeed his Old Etonian school chum at No 10. Mr Johnson previously insisted he had less chance of taking the top job than being "reincarnated as an olive" but his protestations have done little to disguise his leadership ambitions. After leading the Brexiteers to victory his stock among the widely Eurosceptic Conservatives grassroots will be higher than ever. But Tory leadership contests have a funny habit of failing to return the dead cert.

:: Michael Gove

The Justice Secretary has seen his public profile increase over the last few weeks and, bar the occasional sticky moment, he is generally regarded to have had a good campaign. Mr Gove, whose once close friendship with Mr Cameron has come under strain as the rough and tumble of the battle took its toll, has seen his poll ratings shoot up and Ladbrokes gives him 5/1 odds of moving into Downing Street.

:: Theresa May

Hanging on to the Home Secretary brief, which notoriously ruins political careers, for six years shows Mrs May's durability. Although a Remain supporter, she disappeared off the radar during the campaign, leaving her relatively unscathed. No fan of Mr Cameron, she has been quietly courting the party's rank and file in readiness for his departure and is placed by the bookies as second to Mr Johnson.

:: George Osborne

The Chancellor's hopes of moving next door have faded dramatically. An upturn in economic fortunes under his stewardship saw his popularity in the party increase but Mr Osborne is damaged by his inextricable links to the Prime Minister. Backbenchers said his decision to back Remain ensured any leadership bid was dead in the water.

:: Stephen Crabb

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. But the sudden contest may come a little too soon for him to make much headway.

:: Ruth Davidson

The Scottish Conservative leader has impressed many with her performance during the campaign and electoral success north of the border last month. But a Westminster seat would need to be found for her to have a viable shot at the top job. Ms Davidson has also suggested such a move is not for her, describing life at No 10 as lonely.