Theresa May never seemed to appreciate the importance of tempo in politics. She was not good at surprising, disrupting and confusing her opponents. Boris Johnson has learned from her mistakes.

From the moment he started running for the Conservative leadership, he has confounded expectations. Almost the first thing he did was to say that, if he became prime minister, he would take Britain out of the EU, deal or no deal, on 31 October.

At first, it seemed an odd mistake. He can’t possibly guarantee that, I thought: he knows he faces a majority in the House of Commons opposed to any likely deal, and a different majority strongly opposed to leaving without a deal.

Yet his determination to deliver the undeliverable has scattered his opponents before him. This week saw the vindication of his strategy. It may not last, but the groups arrayed against him in the Commons are squabbling with each other about their failsafe scheme to block a no-deal Brexit.

The plan depends on the opposition parties and Tory rebels uniting behind a temporary prime minister to replace Johnson, who would agree a Brexit extension with the EU and preside over a general election. Jeremy Corbyn, who has at least some understanding of tempo in politics, took the initiative with his letter to other opposition leaders and four Tory rebels, suggesting that he should be the temporary prime minister.

But he made a mistake in failing to send a copy to Anna Soubry, leader of the Independent Group for Change, which may have only five MPs, but that is four more than the Green Party, and he wrote to Caroline Lucas. Soubry has condemned Corbyn’s plan as a terrible idea.

Jo Swinson, the new leader of the Liberal Democrats, also fell into Corbyn’s trap by saying he was the wrong person to be the caretaker prime minister. This is true and was, therefore, a big mistake. The way to defeat a proposal of that kind is to say, “Yes, let’s talk about it,” and to wait for it to collapse under the weight of its own contradictions.  Corbyn is not the best candidate to maximise the votes of the Tory rebels who are essential to any plan to block a no-deal exit. It would have become clear that Kenneth Clarke or Harriet Harman would be better placed if all the anti-no-deal forces in the Commons had engaged in open discussions.

As it is, the opponents of no deal are playing into Johnson’s hands. If they cannot make the caretaker prime minister scenario work, they will have to rely on trying to pass legislation from the backbenches – which is less certain to succeed.  It may be possible to pass a law like the Cooper-Letwin act in April, requiring the prime minister to seek an extension to the Brexit deadline – but that act was never tested, because Theresa May accepted the will of the Commons and said she would ask for an extension anyway.

Johnson is not going to do that. He might be required by law to ask for an extension, but compelling him to agree terms with the EU would need further laws to try to bind his hands.

Meanwhile, Johnson’s disruption of expectations has changed public opinion. An Opinium poll last weekend found that 46 per cent of people said that, if he couldn’t get a deal through parliament, Britain should leave the EU without a deal. This shift in public opinion adds to pressure on MPs to allow Johnson to drive towards a no-deal Brexit, and it puts him in a stronger position to fight the election, whenever it comes.

Johnson has been prime minister for just three weeks, but in that time he has pushed his opponents off balance and exposed their disunity and poor leadership. The chances of Britain leaving the EU without a deal on 31 October have risen sharply.

John Rentoul, The Independent