The Chairman of the Commons Public Administration Committee has urged MPs to report any attempt to “blackmail” them over their support for a no confidence motion against Boris Johnson to the Metropolitan Police.

William Wragg issued the advice the day after the defection of a former Tory MP to Labour which has said to have  “calmed nerves” of those jostling for Boris Johnson to resign.

Christian Wakeford dramatically switched sides on Wednesday, refusing to “defend the indefensible” over alleged breaches of Covid rules.

Mr Wragg is one of a handful of Tory MPs to have said publicly they have submitted a letter to the chairman of the backbench 1922 Committee Sir Graham Brady calling for a no-confidence vote.

Speaking as the committee prepared to take evidence from the Cabinet Office minister Stephen Barclay, he said the conduct of the Government whips office threatening to withdraw public funding from MPs’ constituencies may have breached the Ministerial Code.

Read William Wragg's statement concerning 'blackmail' in full

Mr Wragg said: “In recent days, a number of Members of Parliament have faced pressures and intimidation from members of the Government because of their declared or assumed desire for a vote of confidence in the party leadership of the Prime Minister.

“It is, of course, the duty of the Government whip’s office to secure the Government’s business in the House of Commons.

“However, it is not their function to breach the ministerial code in threatening to withdraw investments for Members of Parliaments’ constituencies which are funded from the public purse.

“Additionally, reports to me and others of members of staff at No 10 Downing Street, special advisers, Government ministers and others, encouraging the publication of stories in the press seeking to embarrass those who they suspect of lacking confidence in the Prime Minister is similarly unacceptable.

“The intimidation of a Member of Parliament is a serious matter. Moreover, the reports of which I’m aware would seem to constitute blackmail.

“As such, it would be my general advice to colleagues to report these matters to the Speaker of the House of Commons and the commissioner of the Metropolitan Police, and they’re also welcome to contact me at any time.”

Deputy leader of the Labour Party Angela Rayner hit out at the "shocking" allegations.

Taking to Twitter she wrote: These are shocking accusations of bullying, blackmail bad behaviour from people in positions of power. We need this to be investigated thoroughly.