Back to the backstop

As the prime minister walks up the main staircase in No. 10, he or she must pass the portrait of every previous occupant of the office. It is the British equivalent of the slave standing behind the Roman general and whispering ‘Remember you are mortal’ because the career of nearly every prime minister, no matter how distinguished, has ended in failure.

Theresa May must find two of these portraits particularly haunting. Robert Peel passed the repeal of the corn laws in May 1846 with the backing of the Whigs and others, but was then forced to resign as prime minister the following month as the Tories split. Ramsay MacDonald, the first Labour prime minister, was persuaded that a minority government couldn’t deal with a national crisis and so formed one of national unity in 1931. To this day, he is still reviled by his own party.

Peel and MacDonald provide a reminder of what happens to prime ministers who rely on opposition votes to pass their defining legislation for them. After her historic 230-vote defeat last week, May seemed destined to follow in their footsteps. It was hard to see how she could obtain a majority for a Brexit deal otherwise.

But she was saved from that fate by Jeremy Corbyn’s own tribalism. If Corbyn had stood up on Tuesday night and set out his own conditions for backing a deal, a customs union, say, and continuing alignment with EU social and environmental rules, May would have come under huge pressure to accede to his demands. The great and the good would have urged her to ‘put the national interest first’ and come to an agreement. Many in her own Cabinet would have urged her to do so.