A YouGov survey found that 45 per cent of voters in the UK agreed that, with hindsight, the country was wrong to vote to leave the European Union - compared to 43 per cent who said it was the right move and 12 per cent who said they didn’t know.
It is the first time Brexit doubters have outnumbered those in the pro-Leave camp in a nationwide poll.
Theresa May has placed the UK’s exit from the EU at the heart of her election campaign, promising voters that every vote for the Conservatives is a vote for a stronger Brexit.
But the SNP and Liberal Democrats have both warned against a so-called hard Brexit and demanded concessions on a range of issues, including the rights of EU nationals living in the UK to be protected.
The poll for the The Times also saw the Tory election lead shrinking from 23 points at the end of last week to 16 points.
It had the Tories on 45 per cent, down three, and Labour on 29 per cent, up four.