There are so many paradoxes in our politics. Theresa May’s Brexit deal with the European Union should have been a triumph for the prime minister but it has quickly turned into a disaster. The Conservative leader’s moment of greatest strength has become a crisis of vulnerability, with Tory MPs openly plotting to topple her. And the greatest irony of all is that reaching an agreement on the terms of our departure from the EU has actually made it less certain that we will leave. A Remainer prime minister, who has negotiated a Brexit she never wanted, could be thwarted by the Conservative Eurosceptics who have campaigned for it all their lives.

Until now ambiguity has kept Westminster in suspended animation, but the clarity of the