Brexit-backing Tory Minister Steve Baker admitted the historic vote to leave the EU should have required a 60% supermajority.
The Northern Ireland Office minister and leading Leave campaigner made the comments as he suggested a “50 per cent plus one” majority would not be appropriate for a vote on Irish unification.
The 2016 referendum to end EU membership passed by a split of around 52 to 48 per cent in the UK population – prompting years of turmoil before the country leaves in January 2020.
Mr Baker told a meeting of the British-Irish Parliamentary Assembly (BIPA) on Monday that it would “probably have to be a supermajority” of at least 60% to leave the bloc.
The minister said a higher threshold would have removed the difficulty for politicians and the public to not accept the result – admitting it had caused serious political “trouble”.
Asked if he had any regrets about the Brexit campaign, Mr Baker said: “One regret is that it probably should have been a supermajority.
“That's a huge thing for me to say – because if it was a supermajority we would have lost and we'd still be in. But the reason I say that is if we should have had 60%, everyone would have respected the result.”
He added: “If it had been a 60-40 result, it is inconceivable to me that we would have had all the political difficulty that followed from members of parliament in particular refusing to accept the result.”
The Northern Ireland minister then warned against a “50 per cent plus one” result in any potential Irish unification vote. “Would anyone here seriously want a result of 50 per cent plus a united Ireland in Northern Ireland?”
After some politicians muttered “yes” in response, Mr Baker warned them of the “problem” caused by the simple majority in the Brexit referendum.
He said: “Just think about the problem we've had from having a 50 per cent plus one referendum in the UK and ask yourself do you really want that problem in Northern Ireland – and I don't.”
Last year, Mr Baker apologized for his once “brutal” stance in negotiations with the EU, which he said did not always encourage Ireland to trust the UK government.
Meanwhile, Mr Baker appealed to the Irish government to meet the head of a new commission set up under the UK government's controversial heritage law.
Controversial aspects of the laws include a limited form of immunity from prosecution for trouble-related offenses for those cooperating with the new Independent Commission for Reconciliation and Information Recovery (ICRIR).
“I hope the Irish government will take the opportunity to meet the chief commissioner and talk to him about our work because I really believe it was the unfinished business of the Belfast Good Friday Agreement and my heart goes out to the families of the victims. ” said Mr. Baker.