LONDON — British Prime Minister Boris Johnson asked Queen Elizabeth II on Wednesday to suspend Parliament, throwing down the gauntlet to his critics and causing outrage among opposition leaders who will have even less time to thwart a no-deal Brexit.

Johnson told lawmakers he has decided to ask the monarch to give her speech that outlines the government’s legislative agenda on Oct. 14. Since Parliament is normally suspended before the speech, the decision means opposition lawmakers would be unlikely to have enough time to pass laws blocking the U.K.’s exit from the European Union without a negotiated deal on Oct. 31.

Though Johnson had previously refused to rule out suspending Parliament, the timing of the decision took lawmakers — many of whom are on vacation — by surprise. They reacted with fury, including John Bercow, Speaker of the lower House of Commons, who was not told in advance of Johnson’s plan.

“Shutting down Parliament would be an offense against the democratic process and the rights of Parliamentarians as the people’s elected representatives,” he said. “Surely at this early stage in his premiership, the prime minister should be seeking to establish rather than undermine his democratic credentials and indeed his commitment to Parliamentary democracy.

The pound plunged on the news, down to $1.2196 from almost $1.2300 the previous day.

A day earlier, opposition lawmakers declared that they would work together to try to stop a departure from the European Union without an agreement, setting up a legislative challenge to Johnson and his promise to complete the divorce by Oct. 31, come what may.

Some 160 lawmakers have signed a declaration pledging “to do whatever is necessary” to prevent Johnson from bypassing Parliament in his plans. Johnson’s do-or-die promise has raised worries about a disorderly divorce that would see new tariffs on trade and border checks between Britain and the EU, seriously disrupting business.

Johnson has told European Union officials it won’t be possible to agree a deal on Britain’s departure from the trading bloc without the removal of controversial language on a “backstop,” aimed at avoiding the return of a border between EU member Ireland and Britain’s Northern Ireland. He said at the close of the G-7 summit in Biarritz, France, Monday that he was “marginally more optimistic,” of progress.