Sue Gray may have breached rules with plans to move to Labour Party, Ministers say

And DUP chief whip Sammy Wilson spoke of “double standards” during Commons exchanges on matter yesterday.

Paymaster General Jeremy Quin raised in the Commons on Monday four areas where the senior civil servant may have fallen foul in the "exceptional situation".

Deputy Labour leader Angela Rayner accused Conservative MPs of pursuing "conspiracy theories" spread by former prime minister Boris Johnson and his allies.

Labour confirmed last week that Ms Gray plans to become Sir Keir's chief of staff, after the move was first reported by Sky News.

Mr Johnson and his allies have since seized on it to allege the investigation into the law-breaking parties in Downing Street under his leadership was an attempt to smear him.

Answering an urgent question, Mr Quin said: "The House will recognise this is an exceptional situation, it is unprecedented for a serving permanent secretary to resign to seek to take up a senior position working for the leader of the opposition."

He said there are four rules or guidance for civil servants that are "pertinent", including informing the Advisory Committee on Business Appointments (Acoba).

"The rules state that approval must be obtained prior to a job offer being announced. The Cabinet Office has not as yet been informed that the relevant notification to Acoba has been made," he said.

Other rules relevant to Ms Gray's plans, he said, include impartiality, declaration of outside interests and that contact with opposition parties should be cleared with ministers.

"Regardless of the details of the specific situation, I understand why members of this House and eminent commentators outside have raised concerns," he added.

Mr Wilson asked Mr Quin : “Will the minister agree me that no amount of bluster from the (Labour) front bench will ever hide the double standards of lecturing about accountability and transparency, while at the same time not being prepared to answer a straightforward question as to when they started talking to Sue Gray.”

Mr Quin replied: “I think (he) puts it rather well. It would be very simple just to help put minds at rest by publishing the data, just setting out when the meetings took place, who met who, when and where and that will help reassure the House.”

Labour’s Andrew Gwynne (Denton and Reddish) said: “The faux outrage and wild conspiracies from the party opposite are kidding nobody.”

His Labour colleague Barry Sheerman (Huddersfield) noted the “number of requests for this to be debated”, adding: “Isn’t it the fact that this is a shabby little manoeuvre from the shabbiest government?”