There's a clear frontrunner...
David Cameron has signaled his intent to resign as British Prime Minister after the UK public voted to leave the European Union.
He campaigned to remain in the EU, but the 'Out' campaign won by 51.9% to 48.1% as over one million more people voted to Leave.
Betting trends proved to be an unreliable guide overnight as the UK voted against the market which predicted a 'stay' vote. Paddy Power described the result as "stunning."
Yui Mok / PA Wire
Former London mayor Boris Johnson was the most high-profile supporter of the 'leave' side in the Conservative Party.
His odds have dropped to 8/11 - making him the clear favourite.
Speaking after the British PM signalled that he will step down, Mr Boris said he was "sad" Mr Cameron had decided to stand down, "but I respect his decision" he added.
Mr Johnson said the PM's "bravery" gave the nation its first referendum on the EU, and he described Mr Cameron as "one of the most extraordinary politicians of our age."
He was one of 80 Tory MPs who had earlier signed a letter saying the Prime Minister had a "mandate and a duty" to stay whatever the result.
Stefan Rousseau / IRN
Theresa May is the second favourite, at odds of 9/4. Unlike some of her cabinet colleagues, she has managed to avoid the majority of the mudslinging in the pre-referendum debate.
Would be a popular choice within the party and could 'steady the ship' after the party split on the EU vote over the past months.
Isabel Infantes / EMPICS
Micheal Grove is next - but significantly further back at 5/1.
The Justice Secretary was considered by Number 10 to be "toxic" among the electorate after being removed from his education post in 2014 - but his position at the heart of the 'leave' campaign has put him among those being talked about.
He has repeatedly said he has no leadership ambitions and recently had to withdraw comments comparing economists who backed the 'remain' side to Nazis propagandists.
Additional reporting by IRN