The UK is set to remain in the European Union, according to an on-the-day poll released at 10pm tonight.
The poll, carried out by YouGov, shows the Remain side is set to win the referendum, with 52% of those asked backing the UK staying in the EU.
If the poll is accurate, it would be a hammer-blow for Boris Johnson, whose backing of a Leave vote helped widen a split at the very top of the Conservative Party.
Ukip leader Nigel Farage has already vowed to fight on as he appeared to concede that Remain has won.
Speaking to Sky News, he said: "It's been an extraordinary referendum campaign, turnout looks to be exceptionally high and looks like Remain will edge it.
"UKIP and I are going nowhere and the party will only continue to grow stronger in the future."
While the survey is not a traditional exit poll, YouGov accurately predicted the Scottish Referendum in 2014 using the same method of asking a targeted group of people which way they voted on the day of poll.
Joe Twyman, head of political and social research at YouGov, said: “Today YouGov conducted a survey, going back to the same people we spoke to yesterday to find out how they actually voted. The survey found a small move to Remain and based on these results we expect the United Kingdom to continue as a member of the European Union.
“Remain are on 52% with Leave on 48%.
“The results are close and it too early to call it definitively. But these results, along with the recent trends and historical precedent, suggest a Remain victory is the more likely outcome.”
While Farage appears to have conceded, Leave,EU - the organisation run by Ukip donor Arron Banks - appear more confident of victory.
A statement from the campaign group said: "Leave.EU has conducted a nationwide poll of over 10,000 people over the last 48 hours. The results are as follows:
"Our poll was conducted between 1800 on June 21st and 1800 on June 23rd and suggests a narrow Leave victory. The poll excludes those that said they would not be voting or undecided."
The official result is set to be announced by the Electoral Commission in Manchester on Friday morning.
However, with the regional venues set to announce their results throughout the night, the direction of travel will become clear long before the official declaration.
The first result is expected to come in around 12.30am, with a flurry of announcements between 4am and 7am.
Voting got underway in today’s historic referendum in Gibraltar at 6am UK time, before polling stations opened across the rest of the UK an hour later.
Torrential rain in southern England caused transport delays, leading to concerns some people may not be able to get to polling stations before the 10pm cut off time.
While people weighed up the global, national and personal implications of either a Remain or Leave vote, many looked on the lighter side of the whole debacle.
#DogsAtPollingStations made a return, as people across the country posted cute pictures of their pups as they went to the ballot box.
The phrase “93yr mum” began trending on Twitter after one man's proud tweet: