Former British Prime Minister Tony Blair on Thursday said he would advise Labour Party lawmakers to vote down a Brexit divorce deal that Theresa May is trying to clinch with the EU.

Nearly six months before the United Kingdom’s exit from the EU, there is little clarity about how the world’s fifth largest economy and its preeminent international financial centre will trade with the EU after Brexit.

Blair, Labour prime minister from 1997 to 2007, said voters should be given another referendum on whether to stay in the EU as he saw deadlock in British politics.

If May  can strike a deal with the EU, she has to get it approved by the British parliament which is divided on Brexit.

Labour has indicated it is likely to vote down any deal May brings back.

When asked if he would advise Labour lawmakers to vote down a possible deal, Blair said: “It really is difficult.

“The alternatives are all worse because if you do get to a blockage in parliament that is what opens up the possibility of going back to the people.

“My view is this only happens if there is blockage in parliament.

“However, if there is blockage in parliament it is a very simple argument. You say look we have been two and a bit years trying to reach an agreement that works, parliament is blocked.”

Both opponents and supporters of Brexit agree that the divorce is Britain’s most significant geopolitical move since World War Two.

However, they cast vastly different futures for the 2.9 trillion dollars UK economy and the world’s biggest trading bloc.

Blair has repeatedly called for reversing Brexit, echoing other critics such as French President Emmanuel Macron and billionaire investor George Soros, who have suggested that Britain could still change its mind.

Blair said that if Brexit did happen, the economic dislocation would be such that the United Kingdom would have to pitch to investors that it would be the best place in the world to do business.