LONDON —Queen Elizabeth II approved a request by Prime Minister Boris Johnson on Wednesday to shut down Parliament for several weeks ahead of Britain’s upcoming departure from the European Union, a startling maneuver that will rob his opponents of time to thwart a no-deal Brexit.

The announcement of Johnson’s plan prompted expressions of outrage from many lawmakers, who said they are being deprived of their democratic voice on Britain’s most momentous decision in generations. It increased the chances that the country will sail out of the European Union at the end of October with no transition deal to buffer its passage, a move analysts say could cause major economic turmoil, including food and fuel shortages.

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Johnson told reporters he had asked the queen, who is on holiday at her Scottish estate of Balmoral, to give her usual annual speech outlining the country’s legislative agenda in mid-October, effectively suspending Parliament between Sept. 11 and Oct. 14.

The queen acceded to the prime minister’s request, as is customary.

In an official statement, the Privy Council confirmed that the queen had agreed to prorogue — or suspend — Parliament no sooner than Sept. 9 and no later than Sept. 12. Jacob Rees-Mogg, the leader of the House of Commons, Natalie Evans, the leader of the House of Lords, and Mark Spencer, the chief whip, were at Balmoral to deliver the request.

Absent a delay, Britain will leave the European Union on Oct. 31.

Johnson denied claims that Brexit is the reason he sought the new timetable, telling reporters he wants a new session of Parliament so he can lay out the government’s “very exciting agenda.”

He added that there would be “ample time” for lawmakers to debate Brexit.

© Francois Mori/AP Britain's Prime Minister Boris Johnson gestures during his final press conference at the G7 summit Monday, Aug. 26, 2019 in Biarritz, southwestern France.

The move to prorogue Parliament at this crucial time in the Brexit process angered even some lawmakers in the governing Conservative Party.

A petition launched on the British Parliament website calling for the government not to suspend the body quickly exceeded 100,000 signatures, the number needed for it to be considered for a parliamentary debate. The latest tally was 470,000, and it was rocketing skyward, although any such debate would not lead to legislative action.

Proroguing Parliament is not unheard of — it happens most years. But the five-week gap this time is unusually long. In 2017, Parliament was prorogued for six days; in 2016, for five days; in 2015, for three days. Moreover, doing it in the weeks ahead of Brexit dramatically shortens the timetable for lawmakers to pass any other kind of legislation, such as a law that could prevent a no-deal Brexit.

A “constitutional outrage,” said John Bercow, the speaker of the House of Commons, in a statement. “However it is dressed up, it is blindingly obvious that the purpose of prorogation now would be to stop Parliament debating Brexit and performing its duty.”

Labour Party leader Jeremy Corbyn vowed to fight Johnson’s move.

Opposition leaders had talked about forcing a vote of no confidence in Johnson’s government sometime before late October. Wednesday’s maneuver, if successful, would drastically narrow their window to next week. But it is unclear whether they have the votes either to install a new government or force a new election.

“Boris Johnson’s attempt to suspend parliament to avoid scrutiny of his plans for a reckless No Deal Brexit is an outrage and a threat to our democracy,” Corbyn wrote on Twitter. “Labour will work across Parliament to hold the government to account and prevent a disastrous No Deal.”

© Victoria Jones - WPA Pool/Getty Prime Minister Boris Johnson and Queen Elizabeth on July 24

The controversy drew the attention of President Trump, who struck up a friendly relationship with Johnson over the weekend at the Group of Seven summit in Biarritz, France.

“Would be very hard for Jeremy Corbyn, the leader of Britain’s Labour Party, to seek a no-confidence vote against New Prime Minister Boris Johnson, especially in light of the fact that Boris is exactly what the U.K. has been looking for, & will prove to be ‘a great one!’ Love U.K.,” Trump wrote on Twitter.

In the rest of the European Union, leaders have grown increasingly resigned to the possibility that Britain will leave without a deal. But there was anger — and some shock — that it could apparently happen with minimal input from Parliament.

“We could see a no-deal Brexit coming. Now it’s a no-debate Brexit that’s looming,” tweeted Nathalie Loiseau, a member of the European Parliament and a top ally of French President Emmanuel Macron. “What disease is British democracy suffering from to fear a debate before making one of the most important decisions in its history?”

British lawmakers return to Parliament next week following their summer recess, or break. Parliament then normally shuts down in late September when the political parties hold their annual conferences. The suspension will extend that period.

“Normally, when we prorogue Parliament, it’s for five or six days maximum between sessions, and I think this is pretty unprecedented,” said Dominic Grieve, a Conservative lawmaker. He called Johnson’s move “outrageous.”

Grieve said he would consider voting against his own party if a no-confidence vote is called. Constitutional experts agreed that the length of the suspension — five weeks — is highly unusual.

The latest developments follow a meeting on Tuesday by opposition lawmakers to try to craft a strategy for thwarting a no-deal Brexit. In a rare show of unity, leaders of opposition parties agreed that they would prioritize trying to pass legislation to that end.

“Unless MPs come together to stop him next week, today will go down in history as a dark one indeed for UK democracy,” said Nicola Sturgeon, the leader of the Scottish National Party.

Britain’s mop-topped prime minister has laid out his timetable: He says that Britain will leave the E.U. with or without a deal by Oct. 31. He insists that he wants a deal, but his four-page letter to E.U. chiefs and talks last week with the leaders of France and Germany have yet to yield a breakthrough.

During a week of negotiations with other E.U. leaders, including over the weekend at the G-7 summit, Johnson left his counterparts feeling that he would prefer to exit the E.U. with a deal, according to officials briefed on the conversations who spoke on the condition of anonymity to discuss private assessments.

But leaders including Macron and German Chancellor Angela Merkel felt Johnson was ready to depart on the October deadline if no politically feasible deal materializes in the meantime, senior officials said.

The officials said they felt Johnson was setting an impossible task by demanding that the E.U. strip out an insurance plan designed to ensure that the border between Ireland and Northern Ireland remains open after Brexit.

Many observers think Johnson is ramping up for a possible early general election, which he says he doesn’t want. At present, he has a working majority of just one.

Nigel Farage, the leader of the Brexit Party, tweeted that he would consider a pact with the Conservative Party in a general election if Johnson exits the bloc without a deal. But if Johnson strikes a deal with the E.U., Farage said, his Brexit Party “will fight him every inch of the way.”

karla.adam@washpost.com

michael.birnbaum@washpost.com

Birnbaum reported from Brussels. Jennifer Hassan in London and Quentin Ariès in Brussels contributed to this report.