As rebels geared up to defeat Boris Johnson over the issue, the former cabinet minister revealed he had been in close contact with Bercow to discuss “procedures” in parliament ahead of next week’s constitutional showdown.
Letwin is part of a cross-party group which aims to seize control of the Commons timetable and then pass a bill forcing the PM to seek an extension of the UK’s EU membership beyond October 31.
The rebel group, including former ministers Hilary Benn, Dominic Grieve and Philip Hammond, has spent weeks working with parliamentary officials and other experts to ensure they draft “watertight” legislation to block a no-deal exit.
After a Daily Telegraph report that Bercow had interrupted his family holiday in Turkey to contact rebels, Sir Oliver denied he had been “cooking up a deal with the speaker”.
But he did confirm they had been in contact, telling BBC Radio 4’s Today programme: “It is perfectly true that for many months I’ve been talking both to the clerks and the speaker and that’s the appropriate thing to do if they want to establish what the procedures are, and we’ll go on doing that.”
Letwin stressed: “The action here is on the part of MPs, not on the part of the Speaker”.
Although Bercow will have no role in personally voting for any new bill that binds the PM’s hands, he will play a crucial part in tearing up precedent to allow an emergency motion to let backbenchers seize control of the Commons business.
Under one plan, MPs would on Tuesday night pass a ‘Standing Order 24’ motion allowing them to take control of the timetable on Wednesday, possibly shifting prime minister’s questions and a planned spending review by the chancellor.
Bercow broke off from his summer break this week to issue a withering statement attacking the “constitutional outrage” of the PM’s prorogation move.
Lord Lisvane, former Clerk to the Commons, also hit back at claims by Commons leader Jacob Rees-Mogg that it was unconstitutional for the Speaker to have made such an intervention.
“The house’s presiding officer is also the representative of its interests. And if he sees those interests being damaged or threatened, I think it’s reasonable for him to say something about it,” Lisvane said.
As Johnson once again warned that rebel MPs risked undermining the government’s negotiating stance with Brussels to get a deal, Letwin said such claims were untrue.
“I never have believed this thesis that a negotiated deal is going to arise by threatening to withdraw from the EU.
“It’s not a threat [Brussels responds to]. It’s not going to be done by threats.”
And he disagreed with some fellow Tory MPs who are reluctant to tie the PM’s hands until after the EU summit in mid-October.
“I’m concerned about how we can ensure that Britain doesn’t make a sudden, disorderly, undemocratic, no-deal exit on 31 October. I believe that there probably is time.
“I hope that Parliament will take a series of actions that by the end of the week mean that Boris Johnson knows that as prime minister that if doesn’t get a deal he is going to have seek an extension.”
Deputy Labour leader Tom Watson, who is joining a legal challenge to the prorogation, revealed that he was involved in the rebel talks about a bill.
“I have taken advice on legislative solutions to challenge the Prime Minister’s action to stop us crashing out of the EU without a deal. I am in discussions with colleagues in other parties and a Bill to achieve this outcome”
In a TV clip Johnson warned that the Commons could distract from his increased contacts with Brussels to get a deal.
“We are coming up to the last period before we leave on October 31 and in that period Parliament is going to have a lot of time still - they have spent three years debating Brexit, by the way, without actually getting it over the line - they are going to have a lot of time for further consideration.”