The YouGov study of four common questions regularly included in nearly 150 Brexit surveys showed a steady shift towards the Remain camp.
According to the survey, which was commissioned by the Evening Standard, Leave campaigners stayed ahead by a margin of two percentage points following the June 2016 referendum. The pro-Brexit campaign saw its lead cut in half during the first six months of the 2017.
But the gap was turned into a disadvantage for Brexiteers around the middle of last year, when the pro-EU camp opened a two-point lead.
In 2018, the Remainers have stayed ahead with an average lead of around four points, roughly the opposite of the 2016 referendum’s result (52 percent to 48 percent).
“The weight of evidence means that we can be as good as certain that, at least as far as the polls are concerned, Remain is now ahead of Leave,” said Anthony Wells, director of political research at YouGov.
The study found that the turnaround in support for Brexit is driven by people who did not vote first time and now said they supported staying in the EU.
The other reason, the study suggested, was the number of Labour Party supporters who voted for Brexit but later on changed their mind because of party leader Jeremy Corbyn’s pro-EU views.
According to the study, the deaths of older people who voted to leave and an increase among more pro-Remain teenagers who are now eligible to vote could be another contributing factor.
The survey comes as Prime Minister Theresa May’s Brexit policies are in tatters following an embarrassing rejection of her so-called Chequers plans by EU leaders and an approaching deadline of March 2019 to finalize the divorce.
The PM also faces strong opposition from Labour and other parties in Parliament, who want the lawmakers to have a say on the outcome of the EU negotiations.