Former British leader Tony Blair said there was a 50-50 chance of another Brexit referendum as Prime Minister Theresa May will be unlikely to secure a parliamentary majority for any divorce deal, Reuters reported.

Less than six months before Britain leaves the European Union, there is little clarity about how post-Brexit trade between the EU and the world’s fifth largest economy will function.

If May can strike a deal with the EU, her minority government then has to get it approved by a deeply-divided parliament.

“Whatever Brexit is on offer today is going to result in significant economic harm,” Blair, former head of the opposition Labour Party and prime minister from 1997 to 2007, told Reuters. “I think the odds are now 50 percent that you will get another (referendum) vote.”

“I still believe it is possible that Brexit is stopped,” he said. “There is no majority in parliament for any proposition that the prime minister brings back.”

Both opponents and supporters of Brexit agree that the divorce is Britain’s most significant political and economic move since World War Two, though they cast vastly different futures for the $2.9 trillion UK economy and the world’s biggest trading bloc.