The battle between Government and Parliament over control of the Brexit process saw the Commons Speaker again clash with Tory MPs as he insisted he would not be "pushed around by agents" of Whitehall.

Amid reports that a conspiracy of backbenchers was seeking to take control of parliamentary business from UK ministers - dubbed a “very British coup” by one Government source - John Bercow told one minister to "lump it".

The Speaker was heckled by Tory MPs as he insisted that people should understand any MP could ask for a meeting with him; it emerged the day before Mr Bercow controversially allowed a vote on Conservative Remainer Dominic Grieve’s amendment to force Theresa May to swiftly produce a Plan B should her Brexit deal be defeated, he had met the former Attorney General.

The Speaker insisted the “notion that some particular advantage is given to a specified individual or a little coterie as part of a secret plot in private apartments is…staggeringly absurd”.

In response to another Point of Order, Mr Bercow declared: "I will stand up for the rights of the House of Commons and I will not be pushed around by agents of the executive branch.

"They can be as rude as they like, they can be as intimidating as they like, they can spread as much misinformation as they like, it won't make the slightest bit of difference to my continuing and absolute determination to serve the House of Commons.”

Earlier, Boris Johnson warned about any parliamentary move to try and thwart or frustrate Brexit, saying it would be seen by voters as a betrayal.

The former Foreign Secretary told LBC radio: "I notice all this stuff about complicated jiggery-pokery for Parliament to frustrate the deal. I don't think that really can be done. We are really playing with fire."

His remarks came after three senior Conservative backbenchers – Sir Oliver Letwin, Nicky Morgan and Nick Boles – said they would publish a bill that would seek, if the Government failed to get a compromise deal through Parliament, to hand the responsibility over to the Commons Liaison Committee made up of all the committee chairmen.

Its proposal would then go back to MPs for a vote and, if passed, would “legally require” ministers to implement it.

Mr Boles said: "What MPs need to understand is that if[the Prime Minister] fails, then we are not going to allow a no-deal Brexit to happen and that is what this bill secures."

But his Tory colleague, Sarah Wollaston, who chairs the committee, tweeted: "Parliament can propose legislation for Government to take forward & it can amend or block it but backbench MPs cannot take over conducting a complex international negotiation."

Ben Wallace, the Security Minister, also took to Twitter, saying: “Sorry Nick, none of us voted for committee chairs to be the Executive. As you know their posts are party allocated and they elected to scrutinise policy NOT to usurp the democratically elected Government.”

Asked whether the Prime Minister was concerned about her Tory colleagues’ plan for Parliament to take control of the Brexit process, her spokesman replied: "Any attempt to prevent the Government from meeting all the legal conditions for an orderly exit at this moment of historic significance is extremely concerning."