LONDON — British Prime Minister Boris Johnson has called on the European Union to "rethink" its refusal to renegotiate the Brexit deal, as he pledged to throw all his energy into making sure Britain leaves the bloc on time on Oct. 31.

Addressing a rowdy session of Parliament for the first time since becoming prime minister, Johnson pledged Thursday to take a new approach. Rejecting the withdrawal agreement negotiated by his predecessor, Theresa May, he insisted that while he wanted a deal, the country was better prepared than widely believed to leave without one.

"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 said. "If they do not, we will, of course, have to leave — the U.K. — without an agreement."

“In the 98 days that remain to us we must turbocharge our preparations to make sure that there is as little disruption as possible to our national life,” Johnson told parliament.

Johnson has less than 100 days to make good on his promise to deliver Brexit by Oct. 31 after what he called "three years of unfounded self-doubt" under May's government.

Yet Britain will struggle to get the bloc's full attention during August, a sleepy holiday period in much of Europe.

The EU is adamant it will not renegotiate the agreement struck with May on the terms of Britain's departure and the framework of future relations. Without it, Britain faces a chaotic Brexit that economists warn would disrupt trade by imposing tariffs and customs checks between Britain and the bloc, send the value of the pound plummeting and plunge the U.K. into recession.

Nonetheless, Johnson is bulldozing his way forward to leave the EU at the end of October, "come what may."

To accomplish it, he culled many members of May's Cabinet within hours of taking office, replacing them with a group of loyal Brexit supporters.

The new line-up includes Foreign Secretary Dominic Raab, Treasury chief Sajid Javid, Home Secretary Priti Patel and House of Commons leader Jacob Rees-Mogg.

Many of the new ministers worked with Johnson in the 2016 referendum campaign to leave the EU, as did much of Johnson's new backroom staff.

Three years after the "leave" campaign won that referendum by 52%-48%, Britain remains one of the 28 members of the EU.

Brexiteers blame May, who resigned in defeat after failing — three times — to secure Parliament's backing for her divorce deal with the bloc. Her allies point out that it was hard-core Brexit supporters who sank the deal because they felt it kept the U.K. too closely bound to the EU's rules.

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 the brash Brexit advocate faces the same problems that May faced: 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 — include some of the May government ministers swept away by Johnson — are vowing to put up a fight when Parliament returns from a six-week summer break that starts Friday.

That has led to speculation that lawmakers could topple the government in a vote of no-confidence.

Johnson could also call a snap fall election in hopes of gaining a majority in Parliament for his plans.

The country's next scheduled election is not until 2022 but can be brought down at any time before then if the government does not command the confidence of the majority of the House of Commons.

"We live in a parliamentary democracy, you can never rule out general elections in that sense," said Rishi Sunak, the new chief secretary to the Treasury.