GQR’s polling on Brexit, published by POLITICO, shows just how closely fought any future referendum campaign would be. Growing calls for a second referendum, given further weight by Labour’s opening a path to a possible vote at its conference last week, put the idea firmly on the table. But any such campaign would be fraught with risk for those seeking to keep Britain inside the bloc.

Our poll shows British voters breaking in favour of remaining in the EU, rather than leaving with a deal negotiated by Theresa May, by the narrow margin of 40-39%. Given the significant number who couldn’t make up their mind and the uncertainty around what the specific terms of the referendum would be, it’s as good as tied. The record also suggests Remain would have a hill to climb in the campaign. Three months before the 2016 referendum our polling showed Remain had a slight lead, but Leave had the stronger arguments. In any repeat, Remain campaigners would have their work cut out to neutralize Leave’s arguments about immigration and sovereignty, which ultimately tipped the balance in 2016.

Furthermore, our new poll shows a perhaps surprising appetite for the harshest form of Brexit. In a question pitting May’s deal against leaving with no deal, 35% opted for the deal and 33% for no deal. While the public would be more open to sending the government back to the negotiating table, with 48% saying they would vote to negotiate a new deal versus only 22% who would accept May’s deal, this is unlikely to make it on to the ballot should a second referendum take place.

A new public vote is still a plausible means for Britain to reverse Brexit, but campaigners need to be prepared for another close fight if it gets that far.

GQR surveyed 1447 adults in Great Britain online between 24 and 26 September. Data were weighted to be nationally representative by gender, age, region, social grade, ethnicity and vote in the 2016 EU referendum.

Data tables are available here.