LONDON (AP) — British Prime Minister Boris Johnson urged the European Union on Thursday to rethink its refusal to renegotiate the Brexit deal, setting himself on a collision course with both the bloc and his own lawmakers over his vow to leave the EU by Oct. 31.
Addressing a rowdy session of Parliament for the first time since becoming prime minister a day earlier, Johnson pledged to deliver Brexit and a "broader and bolder future."
He was heckled loudly by an opposition determined to thwart him, with Labour Party leader Jeremy Corbyn dismissing Johnson's "arm-waving bluster."
Rejecting the Brexit withdrawal agreement negotiated by his predecessor Theresa May, Johnson insisted that while he wanted a deal, it could only happen if the EU budged, especially on an insurance policy for the Irish border that has been rejected by U.K. lawmakers.
"I hope that the EU will be equally ready and that they will rethink their current refusal to make any changes to the Withdrawal Agreement," he told Parliament during the more than two-hour session. "If they do not, we will, of course, have to leave — the U.K. — without an agreement."
The EU repeated, for the umpteenth time, its insistence that it will not renegotiate the agreement on the terms of Britain's departure that it struck with May.
"The European Union's position remains unchanged. ... We will not reopen the withdrawal agreement," said European Commission chief spokeswoman Mina Andreeva.
Without a divorce deal, Britain faces a chaotic Brexit that economists warn would disrupt trade by imposing tariffs and customs checks between Britain and the bloc. They say that could send the value of the pound plummeting and plunge the U.K. into recession.
Nonetheless Johnson, who won an election of Conservative members to replace May as party leader and prime minister, has vowed to complete Brexit and silence "the doubters, the doomsters, the gloomsters" who believe it can't be done.
But details remain scarce about how Johnson's government would alleviate the economic shock if Britain crashed out of the EU's huge free-trading bloc, ripping up decades of agreements regulating everything from aviation to drugs to telecommunications.
Johnson has less than 100 days to make good on his promise to deliver Brexit by Oct. 31. Yet Britain will struggle to get the bloc's full attention during August, a sleepy holiday period in much of Europe, and the U.K. Parliament is due to start a six-week summer break on Friday.
He said he was ready to talk to EU leaders "whenever they are ready to do so," and also promised to "turbo-charge" planning for a no-deal exit, with millions more allocated to a public information campaign for citizens and businesses.
Earlier Thursday, Johnson also held the first meeting of his new Cabinet, which he has filled with loyal Brexit supporters. They include Foreign Secretary Dominic Raab, Treasury chief Sajid Javid, Home Secretary Priti Patel and House of Commons leader Jacob Rees-Mogg. Many of them worked with Johnson in the 2016 referendum campaign to leave the EU, as did much of Johnson's new backroom staff.
Despite the new lineup, he faces the same problems that bedeviled May: heading a government without a parliamentary majority and with most lawmakers opposed to leaving the EU without a divorce deal.
Lawmakers who oppose a no-deal Brexit — including some of the Conservative ministers in May's government who were swept away by Johnson — are vowing to put up a fight when Parliament returns from its break in September.
"This House will stop the prime minister," said Scottish National Party lawmaker Ian Blackford, who branded a no-deal Brexit "economic madness."
It's almost certain that opposition lawmakers will try to topple Johnson's government in a vote of no-confidence in September. There also is rising speculation that Johnson could call an early fall election in hopes of gaining a majority in Parliament for his plans.
The country's next scheduled election is not until 2022, and Johnson says his priority is Brexit, not an early poll — but he hasn't ruled one out.
In the meantime, Johnson must prove he can deliver on his optimistic pronouncements.
Dozens of lawmakers in Parliament grilled him on details: How would he uphold the government's promise to keep the border between Northern Ireland and EU member Ireland free of customs checks? How would he enforce his promise that all 3 million EU citizens living in Britain can stay?
He batted them all away, offering instead the blustering optimism that have made him one of Britain's most divisive politicians.
"There is every chance that in 2050 ... we will be able to look back on this extraordinary period as the start of a new golden age for our United Kingdom," he said.
Corbyn, leader of the main opposition Labour Party, said the country was worried that "the new prime minister overestimates himself."
"He says he has pluck, nerve and ambition," Corbyn said. "Our country does not need arm-waving bluster but competence, seriousness and, after a decade of division policies for the few, to focus on the interests of the many."
Associated Press writer Raf Casert in Brussels contributed.
Follow AP's full coverage of Brexit and the Conservative Party leadership race at: https://www.apnews.com/Brexit