MOST people in the UK will soon oppose Brexit because of “relentless” demographic changes, according to a new academic report marking one year to leaving the EU.

Published by The UK in a Changing Europe thinktank, it says rising education levels, ethnic diversity and generational change are all pushing public opinion in a pro-European direction.

It estimates that the 52-48 vote for Leave in 2016 will be reversed by 2021, becoming 52-48 for Remain, and reach 54-46 in favour of Remain by 2026.

READ MORE: Theresa May "the block" to getting a deal on Brexit Bill, insists SNP leadership

Authors Professor Rob Ford and Dr Maria Sobolewska of Manchester University said this would not necessarily translate into a clamour to reverse Brexit, as there was still an appetite to curb EU powers, but did point to a demand for closer EU ties.

They said: “The Brexit majority is fragile and on the wrong side of powerful demographic pressures, with eurosceptic social groups shrinking while more europhile groups expand.

“Three overlapping processes of long-run demographic change -university expansion, rising diversity and generational replacement - are all increasing the share of the electorate who hold the socially liberal and cosmopolitan values associated with EU support. These processes of political climate change are slow, but relentless.”

Nicola Sturgeon on Brexit: Scotland’s views have been largely ignored

It added: “While ‘hard’ Brexiteers look to be on the wrong side of demographic trends, a softer form of Brexit could - all else being equal - enjoy broader and more sustainable support in the long run.”

The report accompanies a conference in London today organised by the thinktank at which former Ukip leader Nigel Farage will put a rather more positive case for Brexit.

But the report concluded Brexit had been characterised by “significant political and economic uncertainty” to date, with a lack of direction on multiple policy fronts.

After being 0.6 per cent higher than other G7 members before the EU referendum, UK GDP growth was 0.9 per cent lower last year.

Compared to countries of similar growth before the referendum, UK economic growth is now 1.3 per cent lower than if the country had not voted for Brexit.

Brexit has also increased inflation by an estimated 1.7 per cent.

A chapter by pollster Professor Sir John Curtice suggested people who didn’t vote in the referendum were kicking themselves and nudging recent polls in favour of Remain.

Brexit: Almost everything remains to be decided

He said there had little change in the mood of those who voted Remain and Leave in June 2016, with small, roughly equal numbers switching their positions.

A “slight movement” towards Remain in recent polls, to 52-48 support for staying in the EU, was driven instead by non-voters.

He said: “The principal reason why polls now show a small lead for Remain is that while around one in five (21 per cent) of those who did not vote in 2016 say they would now vote Leave, around a half (51 per cent) state that they would now vote remain.”

The finding suggests the Leave campaign was far more successful in mobilising its support and getting people to the polls, something a data company whistleblower told MPs on Tuesday may have been down to improper conduct by pro-Brexit campaigns.

Prof Curtice said if there was a second EU referendum would again be critical.

He said: “At present at least, the outcome of any second referendum looks as though it could well depend on who did and who did not turn out on the day.

“But that, perhaps, is almost inevitable in a country that is still deeply divided about the path on which it began to embark a year ago.”

He also said there had been increased pessimism" about the likely outcome of Brexit talks.

Countdown to Brexit: Only one in seven thinks Brexit talks are going well

Professor Anand Menon, director The UK in a Changing Europe, said: “When Theresa May triggered Article 50 she said she’d provide citizens and businesses with ‘as much certainty as possible, as early as possible’. One year on, our report shows she has failed to do this.

“Uncertainty reigns. This is having negative consequences for business and key sectors including agriculture, fisheries, aviation, the environment, higher education, the health service and financial services.

“In politics, the lack of an overall Conservative majority has created political instability and unpredictability. In Northern Ireland Brexit is destabilising the region and in Britain tensions between Westminster and the devolveds have been heightened.”

Labour MP Alison McGovern, for the Open Britain campaign, said: “With one year to go until we are supposed to be leaving the EU, the Government still have no idea where we are going, and are still not being honest about what the costs will be.

“This report underlines the complexity of Brexit, and the huge distraction it is creating from the countless other challenges facing our country.

“Nobody voted to be on a rudderless ship, slowly drifting away with the wind out of our sails: but that is exactly what is happening.

READ MORE: Mundell faces calls to resign over handling of EU Withdrawal Bill

“As this grim reality becomes clear, everyone is entitled to ask why we are bothering, and to question whether the immense costs of Brexit are really worth it.”

Foreign Secretary Boris Johnson said the UK should stand by for a “Brexit dividend”.