LONDON (June 27): The UK should start planning to delay Brexit and extend negotiations with the European Union or face the disaster of leaving without a deal, according to former Prime Minister Tony Blair.

In an impassioned appeal for a change of course, Blair will warn that crashing out of the EU with no agreement will be “devastating” for the UK, as he declares himself more worried than ever about the country’s future.

Blair believes Theresa May is allowing Britain to drift aimlessly toward exit day because the premier is so weak as to be “more a hostage than a leader.”

“We cannot go on like this,” Blair will tell the Chatham House think tank in London on Wednesday, according to extracts released in advance by his office. “We should plan now for the possibility we need to extend the March 2019 deadline.”

Blair’s intervention will deepen the divisions within the government over May’s handling of Brexit at a critical time as she prepares to finalize her list of negotiating demands. In his speech, he will also heap pressure on the main opposition Labour Party, which he used to lead, accusing it of failing to play its role in saving the country from ruin.

‘The Final Decision’

“Parliament must assert itself because neither Government nor Opposition can or will,” Blair will say. “Then the people must make the final decision because only they have the right to decide what version of Brexit they want or whether in the light of all they now know they prefer to remain.”

May is heading into an EU leaders’ summit on Thursday at which her European counterparts are set to rebuke her over the slow progress of the negotiations. The UK is due to exit the EU on March 29 but talks are stuck on the terms of the divorce and no serious discussions have started on the kind of trade arrangement the two sides will have in future.

May is struggling to build a consensus within her cabinet on what kind of customs and trade model to propose to the EU. She’s promised more detail in a 150-page plan to be published next month but must first win the support of her most senior ministers.

In his speech, Blair voices his fear that the rise of populism in the West poses a real threat to democracy, raising the specter of a return to the kind of fascist politics that Europe witnessed in the 1930s.

“The populist wave upending Western politics shows no sign of abating,” he will say. “It is difficult to predict whether we are at the crest of the wave which will soon subside or whether it is still building its momentum. But I fear it is the latter.”