Theresa May could face the hardest defeat in 95 years in a Brexit vote

Prime Minister Theresa May is set to see her Brexit deal rejected in the biggest Parliamentary defeat for a British government in 95 years after her last minute pleas for support appeared to fall on deaf ears. The battle now is over not whether May loses, but how badly.

At least 70 of her Conservative Party, as well as sometime allies in the Democratic Unionist Party, are publicly pledged to join opposition Members of Parliament in voting against her agreement Tuesday. That would translate into a defeat by a margin of 150 or more, the largest in over a century. Even if some abstain, a defeat by more than 100 would be the worst since 1924.

May postponed a vote before Christmas in the hope of winning over Parliament with new concessions from Brussels over the so-called backstop intended to ensure the post-Brexit Irish border stays open, but EU leaders’ letters of reassurance were treated with scorn in the House of Commons Monday.

Markets and the EU will be watching Tuesday’s results, scheduled to start at 7 p.m., and the margin of a government defeat will affect how they both respond. A defeat by more than 220 votes could see sterling fall to $1.225, according to Neil Jones, head of hedge-fund currency sales at Mizuho Bank.

Meanwhile, a margin of less than 60 would leave some room for hope, several EU officials said last week, and the bloc may look at fresh ways of making the agreement more palatable to get it across the line.