Calls for a second referendum on Brexit are mounting as Britain approaches the last six months before leaving the EU - but the sands of time could be running out for diehard Remainers.
London Mayor Sadiq Khan this week became the latest big name to call for a vote, joining former prime ministers Tony Blair and John Major and celebrities like football star Gary Lineker.
The Liberal Democrats, the only major political party advocating a vote, will push their message again at a conference on Tuesday.
At the meeting in Brighton, party leader Vince Cable will urge Prime Minister Theresa May to "lead her party and the country by opening her mind to a people's vote on the final deal".
The government is opposed, while the main opposition Labour Party is not supporting the calls but also not ruling out the prospect.
Supporters of a second referendum are also divided over what the actual question might be, including whether it should include a question on staying in the EU.
"What would a second referendum be about? That's not clear at all," said London School of Economics professor Sara Hobolt.
Time is running down, as Britain is set to leave the European Union on March 29, 2019.
In the 2016 referendum, 52% voted to leave and 48% wanted to stay.
Hobolt said polls indicate those proportions have reversed, with 52% who would now back staying in the bloc.
She also pointed to "a marked increase in people's support for a second referendum", pointing to a YouGov poll in July in which 42% of Britons favoured a referendum on the terms of the Brexit deal - against 40% who were opposed.
But Hobolt doubted whether a new vote could take place without the support of either of the main parties.
May said on Monday she thought the only alternative to her blueprint to stay close to the EU on trade would be no deal at all.
But she has said a second referendum on any options would be a "gross betrayal" of British democracy.