Brexit campaigners have been boosted a new poll giving the Leave camp a 10-point lead.
The survey by ORB for The Independent put the scores at 55% to 45% in favour of pulling out of the European Union, after allowing for an individual's likelihood to vote.
That is a four-point jump in support from April when Vote Leave led by 51 to 49 and an exact reversal of the position when the series of surveys began a year ago.
A 56% majority of 2015 Labour voters - seen as pivotal to the result - back continued membership but 44% are pro-Brexit - while Tories are 62% to 38% in favour of divorce from Brussels.
Scotland was the only part of the UK where a majority said they were in favour of staying in.
Among all voters, Remain is behind by 47% to 53%. ORB polled 2,000 people on June 8 and 9.