Hastily convened group plans to force PM to seek article 50 extension if no deal is reached

Rebel MPs from across the political spectrum are gearing up for a historic parliamentary clash next week, after Boris Johnson announced plans to suspend parliament for a critical five-week period in the run-up to Brexit.

Conservative and opposition MPs took part in a series of hastily convened conference calls on Wednesday in a last-ditch effort to prevent a no-deal outcome, after the prime minister confirmed he had obtained permission from the Queen to prorogue parliament.

The surprise decision provoked widespread fury, with Commons Speaker John Bercow describing it as a “constitutional outrage”.

Robert Kerslake, the former head of the civil service, said Whitehall would have to think carefully about whether to put ministers’ instructions into effect. “We are reaching the point where the civil service must consider putting its stewardship of the country ahead of service to the government of the day,” he said.

In a letter to MPs, Johnson insisted the suspension would allow him to focus on his domestic priorities of funding the NHS and tackling violent crime, and parliament would have “ample” time to debate Brexit – but it was widely seen as a bid to curtail MPs’ chances to bind his hands.

The cross-party rebel alliance agreed to focus on fast-tracking legislation aimed at mandating the prime minister to request an extension to article 50 if he fails to strike a new Brexit deal by mid-October.

The fresh scramble to prevent a no-deal Brexit came on a day of extraordinary drama, as:

• The leader of the House of Commons, Jacob Rees-Mogg, flew to Balmoral to receive the Queen’s formal approval for the prorogation plan at a meeting of the privy council.

• Sterling tumbled by more than 1 cent against the US dollar, as investors interpreted Johnson’s ploy as heightening the risks of a no-deal Brexit, before rallying later in the day to close 0.5 cents down.

• Senior EU figures were taken aback, with the European parliament’s Brexit coordinator, Guy Verhofstadt, calling the move, “sinister”.

• A petition against the suspension of parliament rapidly exceeded 800,000 signatures.

• Jeremy Corbyn protested against the move in a letter to the Queen.

• Lawyers for the activist Gina Miller made an urgent application to the high court for a judicial review of the prime minister’s decision.

Parliament will now sit for little more than a week from 3 September, before breaking until 14 October, when a new Queen’s speech will be held setting out what Johnson called “a bold and ambitious domestic legislative agenda for the renewal of our country after Brexit”.

In practice, given MPs do not sit on most Fridays, they are only likely to lose between four and six sitting days in parliament. MPs would have been due to hold conference recess anyway, from 12 September until 7 October.

Play Video Nationwide protests as Boris Johnson suspends parliament – video

But Johnson’s gambit squeezes the time available for rebel MPs to act. Their numbers have been boosted by the departure from cabinet of key members of the “Gaukeward squad”, including former chancellor Philip Hammond, who is expected to spearhead next week’s efforts.

“At a time of national crisis parliament must be able to meet to hold the government to account and to represent our constituents and it is profoundly undemocratic to shut parliament down to stop it doing its job,” Hammond said.

“We are determined parliament will show its resolve to stop a no-deal Brexit … We will have to try to do something when parliament returns next week.”

He could table a vote of no-confidence in Johnson’s government; but Labour have repeatedly said they would not do so unless they were convinced of success – which is deemed unlikely while potential Tory rebels are focused on blocking no deal through legislation.

Donald Trump waded into the row on Wednesday, fresh from showering praise on Johnson at the G7 summit in Biarritz over the weekend. The US president claimed it would be “very hard” for Corbyn to win a no-confidence vote, because Johnson was “exactly what the UK has been looking for”.

Donald J. Trump (@realDonaldTrump) 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.

One senior Labour figure speculated that Johnson’s rationale might be to show that he had been forced into a general election. “Buckle up, summer’s over,” he said.

But Downing Street insists Johnson is focused on getting a new deal with the EU; and is determined not to go to the polls before Brexit day, even if he loses a vote of no confidence.

“We have been very clear that if there’s a no-confidence vote, he won’t resign. We get to set an election date. We don’t want an election, but if we have to set a date, it’s going to be after 31 October,” said a senior government source.

The first hint that something was afoot came when the chancellor, Sajid Javid, cancelled a major speech planned for Wednesday, announcing instead that a slimmed-down spending review will take place next week.

Johnson’s cabinet, which is packed with veterans of the Vote Leave campaign, were only informed of the prime minister’s decision to suspend parliament in a conference call on Wednesday morning – after Johnson had already made a request to the Queen.

It is blindingly obvious that the purpose of prorogation now would be to stop parliament debating Brexit Speaker John Bercow

Downing Street insisted this had been the standard approach to planning a Queen’s speech for previous governments.

During the conference call, the prime minister stuck resolutely to the line that the suspension was simply aimed at paving the way for his new government to press on with its domestic agenda.

No dissent was expressed, the Guardian understands – though one senior Tory source said Amber Rudd was “more reserved” than others. They described the culture secretary, Nicky Morgan, as “enthusiastic as Andrea Leadsom” in supporting the plan.

The health secretary, Matt Hancock, faced ridicule on Twitter, with his letter to fellow candidates during the Tory leadership contest calling on them to rule out prorogation being widely shared.

Hancock warned in the letter that “a policy on Brexit to prorogue parliament would mean the end of the Conservative party as a serious party of government”.

Matt Hancock (@MattHancock) Proroguing Parliament undermines parliamentary democracy and risks a general election. I rule it out and call on all candidates to do the same pic.twitter.com/4aaAK3Tq8M

Allies said he had been referring to the more drastic proposal of proroguing parliament through to exit day – and believes narrowing the window in which MPs can debate and vote on an improved Brexit deal could help it to pass, by sharpening the dilemma for MPs.

The rebels’ plan for averting a no-deal Brexit leans heavily on Bercow’s assistance. In an extraordinary intervention for the Speaker, whose role demands political neutrality, Bercow said Johnson’s move was a “constitutional outrage”.

“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 in shaping a course for the country,” he said.

“I have had no contact from the government, but if the reports that it is seeking to prorogue parliament are confirmed, this move represents a constitutional outrage.”

The rebels believe Bercow, who is often accused of trying to thwart Brexit by Eurosceptic MPs, will grant a request for an emergency backbench debate – known as an SO24 – on the the first day parliament returns, 3 September.

Play Video 1:41 ‘This is a dictatorship’: politicians react to Boris Johnson’s plan to suspend parliament – video

An amendable motion could then be voted on in a matter of days. If successful it would pass to the Lords who would be required to sit in emergency sessions over the weekend of 7 and 8 September. It must have received royal assent before parliament is prorogued, or the Commons would have to start again from scratch when parliament returns on 14 October.

One former Conservative cabinet minister suggested a key rationale for the government’s approach was that, by convention, the Queen’s speech is debated for six days – clogging up the timetable to prevent wrecking manoeuvres.

“They have worked through the options and decided this is their only reasonably safe option for delivery on 31 October,” he said.

Johnson said MPs would get the opportunity to vote on the outcome of the key 17 October European council meeting, at which he hopes a new Brexit deal will be agreed, during the following week, on 21 and 22 October – little more than a week before exit day.

• This article was amended on 29 August 2019. An earlier version suggested that Philip Hammond was among cabinet members who were sacked. In fact he resigned.