Boris Johnson is hoping a bluff will deliver Brexit, but has built a team for a general election just in case

The arrival of a team lead by the divisive Dominic Cummings is a sign the new PM realises his hand may be forced

The Boris Johnson era has begun, with a characteristic bang rather than a whimper. Speaking outside Downing Street, the new prime minister doubled down on his pledge to take the UK out of the EU on 31 October, taking personal responsibility for leaving then with “no ifs, no buts”.

He declared: “Never mind the backstop, the buck stops here.” Bouncing with the optimism and energy that he hopes to deploy to the pursuit of Brexit, he said the “doubters, gloomsters and doomsters” would be proved wrong.

Johnson insisted the prospect of a no-deal exit was only “a remote possibility” because he would win a new EU deal. But, significantly, he began the process of getting his excuses in first: if the UK crashes out, it will be the EU’s fault – anyone but Boris, of course.

His strategy rests on a gamble: if he talks loud enough about no deal, the EU will blink first and offer a better deal. But if it does not, the UK will leave anyway. One flaw in his plan is that the EU knows the Commons might well block no deal.

In the New Labour era, its strategists talked about setting out a “washing line” of key policies so voters knew they hung together. In a characteristic rush, Johnson frantically scattered a long list of domestic policies over his line, including immediate action on social care, schools funding, hospital upgrades, waiting times for GP appointments, more police.

When he mentioned the creation of “free ports”, it felt as if he was offering free everything. Certainly not the case on social care: people will be asked to pay into a fund during their working life to fund their care in old age. Alarm bells will be ringing at the Treasury’s tills at his raft of pledges; they would cost billions that would not be there in the event of a no-deal departure.

Johnson’s list made clear that he does not want his government to be defined by Brexit. Sound familiar? Theresa May said the same, but failed. Despite deserved plaudits at her valedictory prime minister’s questions for her work on modern slavery, domestic violence and mental health, she never had a coherent domestic agenda in three years in Downing Street. Boris might have only three months to make his mark.

Inevitably, Johnson stressed his commitment to the “awesome foursome” of countries that make up the UK. But he will need more than warm words and flying visits to all parts of the kingdom to allay fears about his strategy. It was the possibility that no deal could lead to the departure of Scotland and Northern Ireland, that convinced May she could pursue the option now central to her successor’s strategy.

The threat to the union is real: no deal could fuel public support for Scottish independence. His legacy might just be as the last prime minister of the UK.

If Boris had not achieved his lifelong ambition on the back of the divisive 2016 referendum, he would be better placed to unite the country. He is now a polarising figure, unloved by many Remainers. Pointedly, there was no mention of the 48 per cent in his speech.

He is putting the Vote Leave band back together in Downing Street. Dominic Cummings, the campaign director, will be a senior adviser. A disrupter and challenger of the status quo, his return will not be welcomed by Whitehall following his stint as special adviser to Michael Gove as education secretary.

Cummings will run the prime minister’s office day-to-day while Sir Eddie Lister, the other senior adviser, will oversee links with cabinet ministers and foreign leaders. Other Vote Leave staff set for No 10 include Lee Cain, Robert Oxley, Ben Gascoigne and Oliver Lewis. So now it’s official – the insurgents have taken back control, and will finally take ownership of Brexit rather than carping from the sidelines about the Remainers’ failure to deliver it.

There is another reason why Johnson is hiring them. While he insists he does not want an early general election, he knows he may be forced into one. Remarkably, Labour was better prepared for the 2017 snap election than the Tories, even though it was May who called it. So his tried and trusted 2016 team will be ready for an election – or even, perhaps, a Final Say referendum, for which they would be well qualified after winning the first one.

Whatever happens on Brexit, Boris might also need to change the parliamentary arithmetic to secure approval of his domestic agenda. His working majority is just two, which could fall to one after next week's Brecon and Radnorshire by-election.

“All roads lead to an election by next spring,” one ministerial ally of Johnson told me. “Either to get a majority for no deal, or for his domestic agenda after Brexit.”

Although his list of domestic policies will cheer Tory MPs frustrated by the vacuum under May, one thing will not change. His fate, too, will be determined by one issue – Brexit.