New prime minister claims he can do better deal with EU but will prepare for no deal

Boris Johnson has become the UK’s new prime minister, promising to defy “the doubters, the doomsters and the gloomsters” by completing Brexit with a deal by 31 October.

Standing outside Downing Street after visiting the Queen, he gave a speech infused with patriotic pronouncements, saying the “people who bet against Britain are going to lose their shirts”.

He also tore into Theresa May’s record of failing to deliver Brexit, saying there had been “three years of unfounded self-doubt” under her government and it was “time to change the record to recover our natural and historic role as an enterprising, outward-looking and truly global Britain”.

Johnson told the nation: “I pay tribute to the fortitude and patience of my predecessor and her deep sense of public service.

“But in spite of all her efforts, it has become clear that there are pessimists at home and abroad who think after three years of indecision that this country has become a prisoner to the old arguments of 2016 and in this home of democracy we are incapable of honouring a democratic mandate.

“And so I am standing before you today, to tell you the British people, that those critics are wrong – the doubters, the doomsters, the gloomsters are going to get it wrong again.”

He set out a series of domestic priorities, including more money for schools, hospital upgrades, the police and social care, promising that “the buck stops with me”.

But the major focus of Johnson’s speech was his determination to carry out Brexit within the next 99 days.

“We are going to fulfil the repeated promises of parliament to the people and come out of the EU on 31 October, no ifs or buts,” he said.

“And we will do a new deal, a better deal that will maximise the opportunities of Brexit while allowing us to develop a new and exciting partnership with the rest of Europe based on free trade and mutual support.

“I have every confidence that in 99 days’ time we will have cracked it. But you know what, we aren’t going to wait 99 days because the British people have had enough of waiting. The time has come to act, to take decisions, to give strong leadership and to change this country for the better.”

While Johnson said he believed a deal was likely, he sent a warning shot that he is preparing to blame Brussels if a fresh agreement cannot be reached.

“I say to our friends in Ireland, and in Brussels and around the EU, I am convinced that we can do a deal without checks at the Irish border, because we refuse under any circumstances to have such checks and yet without that anti-democratic backstop,” he said.

“And it is of course vital at the same time that we prepare for the remote possibility that Brussels refuses any further to negotiate and we are forced to come out with no deal not because we want that outcome – of course not – but because it is only common sense to prepare.”

He said preparations for a no-deal Brexit would be stepped up “with high hearts and growing confidence”, pledging that ports, banks, factories, businesses, hospitals, food companies and farmers would be ready.

Johnson was joined outside Downing Street by his partner, Carrie Symonds, who has stayed away from the limelight in recent weeks following the furore over their late-night row.

Members of his new staff also lined up to hear him, including Andrew Griffith, a Sky executive who lent him a £9.5m townhouse and will become his business adviser, and Munira Mirza, a former deputy mayor who will become No 10 policy chief.

Matt Hancock, the health secretary and a key Johnson supporter, had claimed Johnson would deliver a policy-rich speech but there was little detail to the new prime minister’s domestic promises.

Johnson said he would recruit another 20,000 police officers, stop people having to wait three weeks to see their GP, and promised 20 new hospital upgrades, more spending per pupil and an end to the social care crisis.

“That is the work that begins immediately behind that black door and though I am today building a great team of men and women I will take personal responsibility for the change I want to see. Never mind the backstop – the buck stops here,” he said.