The campaign to keep Britain in the European Union appears to be ahead in Thursday's EU membership referendum, according to polling firm YouGov which surveyed people about how they voted, Sky News reported.
A YouGov online poll of nearly 4,800 people found 52 percent of respondents said they voted to remain in the EU and 48 percent voted to leave, Joe Twyman, YouGov's head of political and social research for Europe, told Sky News.
"It's still close and it's still too early to know definitely. But based on the figures that we are seeing, based on the trends that have occured and based on historical precedent we think that 'Remain' are in the strongest position."
The online survey was based on people who were previously polled by YouGov about their voting intentions and who agreed to share their decision with the firm once they had cast their votes, according to YouGov.
British broadcasters are not conducting so-called exit polls -- in which people are asked as they leave polling stations how they voted -- because the EU referendum is a virtually unprecedented event and the margin of error could be too large.
When Scotland held an independence referendum in 2014, a YouGov poll using similar methodology to its poll on Thursday came close to accurately predicting the outcome of the vote.
On Wednesday, the last YouGov poll on the EU referendum had shown the "In" camp moving into a 51-49 percent lead over "Out."
YouGov's 2014 Scottish referendum poll showed the campaign against independence winning with 54 percent of the vote. The official result gave the campaign 55.3 percent of the vote.
However, YouGov and other major pollsters failed to accurately forecast the result of Britain's national election in 2015. (Reporting by Freya Berry and William Schomberg; Editing by Mark Trevelyan)