He picked his words carefully but there was no doubt MP Steve Barclay was left to carry the can for the Government as he stood in for the prime minister.

Cabinet Office minister Mr Barclay led the Government’s response in Monday’s debate and admitted they made a "mistake" by attempting to change standards rules to prevent a Tory MP from being suspended.

He told MPs that, while there were concerns with the way allegations of wrongdoing by MPs are probed, it had been an error for ministers to proceed in the way they did last week as they sought to rip up the current rules.

Responding to the standards reform U-turn, Mr Barclay said: "I'd like, first and foremost, to express my regret and that of my ministerial colleagues over the mistake made last week.

"We recognise there are concerns across the House over the standards system and also the process by which possible breaches of the code of conduct are investigated.

"Yet whilst sincerely held concerns clearly warrant further attention, the manner in which the Government approached last week's debate conflated them with the response to an individual case."

During the three-hour emergency debate, Mr Johnson was accused of "running scared" after deciding to follow through with his visit to an NHS hospital trust in Northumberland on Monday rather than be present to hear MPs' criticisms of his government's handling of the Paterson affair.

Reports suggested the Conservative leader arrived back in London by about 5pm but opted not to return to Westminster for the debate, which went on until 7pm.

Labour leader Sir Keir Starmer accused Mr Johnson of failing to have the "decency" to address the Commons in person.

"Rather than repairing the damage that he's done, the Prime Minister is running scared," said Sir Keir.

Commons Speaker Sir Lindsay Hoyle had opened the debate by imploring MPs to "sort out the mess we're in" as he said the standards row had brought out the "worst" in the Commons.

In the bitter aftermath of the row, Owen Paterson announced he was quitting as MP for North Shropshire after 24 years, blaming the "cruel world of politics".