Remain would be ahead in a fresh referendum on Britain’s EU membership, according to a poll-of-polls tracker headed by the elections expert Professor Sir John Curtice.

Research by the National Centre for Social Research claims that a majority (52 per cent) of British people currently want to stay inside the bloc while 48 per cent would opt to leave.

Using the average share of the vote in six of the most recent polls that have queried voting intention in a second referendum, the organisation launched its rolling tracker in order to “cut through the white noise that surrounds individual polling results”.

After Labour left the door open to backing a new public vote during its annual conference, Sir John, who is a senior research fellow at NatCen, said the possibility of voters being asked again whether or not Britain should leave the EU had “grown”.

But he continued: “It remains far from certain that a second ballot would deliver a the pro-Remain majority that most of those who have been campaigning for another vote seem to anticipate.

“True, Remain enjoys a lead in the polls. But that lead is a narrow one, and there is little sign of it growing. Moreover, it rests quite heavily on the preferences of those who did not vote two years ago, and who by two to one say they would back Remain. Getting them to turn out in any second ballot might yet prove a considerable challenge.

“That said, those in the Conservative Party who would like a ‘hard’ Brexit and who are minded to put pressure on Ms May in next week’s party conference to ‘chuck Chequers’, need to bear in mind that they may not be able to afford to take the risk that failure to back the government tips the country into a second ballot.

“For it seems that such an eventuality could see them lose the prize they secured two years ago.”