LONDON - Polls for a historic referendum in Britain have closed, 15 hours after they opened to torrential downpours and floods in much of south-east England, including the capital city London.
Counting officially began at 382 local counting areas, with the districts of Sunderland and Wandsworth likely to be the first ones to declare their results at about 12.30am (7.30am Singapore time).
The vote is being closely watched not only in Europe but also around the world.
Overseas territory Gibraltar declared first, voting overwhelmingly at 95 per cent for Britain to remain in the EU.
Newcastle declared next, with 65,404 voting to remain against 63,598 voting to leave. The remain vote was much lower than expected.
The Orkney Islands declared 63 per cent for remain.
A huge cheer went up, however, in Sunderland as it was revealed that 61 per cent of voters had chosen to leave the EU.
Sunderland has a large number of older, lower income voters who polls show are more likely to back so-called "Brexit". If Leave had not been strongly ahead here, it could have indicated they would struggle to break through in areas less favourable to Brexit.
Shortly after polls closed, anti-EU figurehead Nigel Farage told Sky News television that it appeared the "Remain" camp would narrowly scrape victory.
It "looks like 'Remain' will edge it", the United Kingdom Independence Party leader said.
A final opinion poll, conducted by YouGov on Thursday, found 52 per cent were backing Britain's membership of the European Union, and 48 per cent wanted to leave.
Storms overnight led to flooding in many areas, including at polling stations, and caused massive disruptions to public transport networks, with trains and London Underground lines severely delayed or cancelled.
Voters complained of being stranded at major train stations such as Waterloo, London Bridge and Victoria during the evening rush hour, unable to get home to vote after services were cancelled.
The Electoral Commission had said that transport woes were not an acceptable reason to apply for an emergency proxy, which allows for someone else to vote on your behalf.
The deadline for applying was 5pm on Thursday.
Some voters were also stranded overseas after French air traffic controllers went on strike.
Valid proxies are given to those with medical emergencies, if their work does not allow them to go to a polling station in person, or if they live overseas.
The estimated turnout for the vote is 83.7 per cent.
After polls closed, lead Leave campaigner Boris Johnson tweeted his thanks to those who voted, saying: "Democracy has been served and we await the verdict of the people."
British Prime Minister David Cameron thanked voters on Facebook.
At a polling station in the borough of Kensington and Chelsea - one of the wealthiest in London - presiding officer John Colman, 70, said postal votes made up 40 per cent of all votes there while proxy votes constituted 15 per cent.
"This gives me the impression that people are determined to vote," said Mr Colman. He estimated a 60 per cent voter turnout by about 7pm for his polling station.
Even on polling day, volunteers were out in full force campaigning aggressively, handing out leaflets and stickers outside train stations and high streets.
One of the last voters to show up to cast his vote in Bow in east London was Shah Hussein, 33, who did not realise it was polling day until he rode by on his bike and saw a sign that said "Polling station".
"The police officer said, 'I'll look after your bike, you literally have five minutes to go in.'
"I'd be so upset if I missed it."
The waiter, who was born in London, said he voted to leave as he thought the free movement of Europeans into the country was depriving Britons of jobs and housing.
The national result is expected at 7am (2pm Singapore time) at the earliest, and Prime Minister David Cameron will also likely make a speech shortly after the result is announced.
