John Bercow has insisted he will “fight with every breath” to prevent Boris Johnson from suspending parliament to force through a no-deal Brexit.
The House of Commons Speaker’s remarks amounted to his strongest signal yet that he is prepared to personally intervene to stop prorogation.
Mr Bercow said he “strongly believes” the Commons “must have its way” and that MPs must continue to sit and debate the issue as the Halloween deadline looms.
"And if there is an attempt to circumvent, to bypass or - God forbid - to close down parliament, that is anathema to me," he told an audience at Edinburgh Fringe.
"I will fight with every breath in my body to stop that happening. We cannot have a situation in which parliament is shut down. We are a democratic society and parliament will be heard.”
It comes after he in June warned the then-contenders in the Tory leadership race to replace Theresa May as Prime Minister that prorogation was not an option.
“That is simply not going to happen. It is just so blindingly obvious that it almost doesn’t need to be stated, but apparently, it does and therefore I have done,” he told the Commons.
MPs who are against leaving the EU without a deal are attempting to find a parliamentary route to block plans for the UK’s exit on 31 October
On Tuesday it became clear that Mr Johnson's Brexit plans may be jeopardised early next month after a court agreed to fast-track a hearing on whether he can legally prorogue parliament.
A judge in Edinburgh agreed to expedite a legal challenge from anti-Brexit campaigners including more than 70 MPs and peers.
Mr Bercow’s remarks came as former Chancellor Philip Hammond warned Mr Johnson he risks betraying the EU referendum result if he forces through a no-deal Brexit by listening to “unelected” saboteurs.
Mr Hammond, who resigned in anticipation of Mr Johnson becoming Prime Minister, urged the Tory leader to take the UK out of the European with a deal in place.
But he said early signs for that "are not encouraging", warning that demands to abolish the backstop has become a "wrecking" stance over a withdrawal agreement.
"The unelected people who pull the strings of this Government know that this is a demand the EU cannot and will not accede to," the Tory backbencher wrote in the Times.
Mr Hammond said he was busting two "great myths" over No Deal, arguing it will be damaging to the nation - both economically and to the union - and that voters do not back the move.
"Most people in this country want to see us leave in a smooth and orderly fashion that will not disrupt lives, cost jobs or diminish living standards, whether they voted Leave or Remain in 2016," he told the newspaper on Wednesday.
"Parliament faithfully reflects the view of that majority and it will make its voice heard. No-deal would be a betrayal of the 2016 referendum result. It must not happen."
Mr Hammond also accused "some key figures in the Government" of "absurdly" suggesting no-deal would boost the UK's economy.
Work and Pensions Secretary Amber Rudd said she would urge Mr Johnson not to take that controversial move as part of his "do or die" commitment for Brexit by the October 31 deadline.