Supporters of the Leave campaign celebrated as the result of the referendum came in [EPA]
Results of UK's EU referendum are close but the Remain campaign appears to be failing to pick up enough support.
The Leave camp has edged ahead in the UK where voters have gone to the polls in a referendum on whether the country should stay in the European Union.
With more than half of the UK's council votes counted on Friday morning, a Brexit is now looking more likely.
The Reuters news agency says the Leave camp has moved ahead to 51.3 percent, with the Remain vote just behind on 48.7 percent, with 171 of the 382 counting areas declared.
UK Independence Party leader Nigel Farage already declared victory in a speech held in London.
"The dawn is breaking on an independent United Kingdom," Farage said to loud cheers at a Leave campaign party.
"I hope this victory brings down this failed project and leads us to a Europe of sovereign nation states, trading together, being friends together, cooperating together, and let's get rid of the flag, the anthem, Brussels and all that has gone wrong."
"Let June the 23rd go down in history as our Independence Day."
Farage went on to accuse Prime Minister David Cameron and former prime ministers Gordon Brown and Tony Blair of "irresponsible, open-door mass-immigration that has damaged the quality of life of ordinary, decent people in this country."
Farage said Prime Minister David Cameron, who campaigned for Remain, should resign "immediately" if the Leave camp win the referendum.
The British pound plunged to a 31-year low as results came in.
The figures delivered a deep shock to financial markets, overturning earlier anticipation of a narrow victory for Remain.
The pound initially soared as polls closed and two opinion surveys put Remain ahead and two leading supporters of the Leave campaign said it appeared the pro-EU side had won.
But it then suffered one of its biggest one-day falls in history, plummeting more than 10 percent in six hours, from about $1.50 to below $1.35 as results suggested a strong possibility the UK would vote to quit the bloc.