Boris Johnson allies Jacob Rees-Mogg, Priti Patel and Nadine Dorries targeted by Partygate probe

The former Prime Minister resigned as an MP with immediate effect after the Privileges Committee ruled that he had deliberately misled Parliament over Covid breaches at No 10.

Also singled out in the report are Michael Fabricant, Mark Jenkinson, Brendan Clarke-Smith and serving minister Lord Goldsmith.

In the report, Committee members complained of "unprecedented and co-ordinated pressure" placed on the investigation.

While the report concedes that such pressure did not affect the outcome of the inquiry, the Committee believes the actions raise significant security concerns.

The Committee said of Boris Johnson's allies: "Their aim was to (1) influence the outcome of the inquiry, (2) impede the work of the Committee by inducing members to resign, (3) discredit the Committee's conclusions if those conclusions were not what they wanted, (4) discredit the Committee as a whole."

The report added: "This unprecedented and co-ordinated pressure did not affect the conduct or outcome of our inquiry.

"However, it had significant impact on individual Members and raised significant security concerns."

Brendan Clarke-Smith, Conservative MP for Bassetlaw, reacted to the report: "Members of Parliament fulfil an important role in society and it is absolutely vital that they are able to scrutinise and comment on any matters relating to their work.

"Having fully respected the processes before me and at no point referring to the committee whilst preparing their previous work, I am shocked and disappointed to be named in this new report.

"This raises serious questions about free speech in a democratic society and my colleagues and I will continue to defend these principles going forward.

Michael Fabricant, Tory MP for Lichfield, said: "I stand by my statement. Some of the members of the Privileges Committee treated their witness, Boris Johnson, with contempt by gestures and other actions.

"Had it been in a law court, the judge would have called them to order. Respect for the Committee needs to be earned."

Fabricant added: "The Committee wishes to be treated as a Court of Law taking witnesses under Oath and pronouncing judgements.

"They must then behave with the dignity and probity of a Court of Law."

Mark Jenkinson, MP for Workington, has responded to being named: "On publication of the previous report I said it had overreached. Prior to publication I had not referred to the committee.

"Yet in another perfect example of gross overreach, the committee use a tweet that did not refer to them and was about the media witch hunt of Boris Johnson."

The committee had been investigating whether Johnson committed a contempt of Parliament by misleading MPs either recklessly or deliberately by denying rule-breaking parties in No 10.

The year-long inquiry found Johnson deliberately misled Parliament about lockdown parties at Downing Street and recommended he be suspended for 90 days.

The cross-party privileges committee has seven members, four of which are Tory MPs, two are Labour and one is from the Scottish National Party.

Johnson has branded the committee, which is chaired by Labour grandee Harriet Harman, a "kangaroo court".

The former prime minister was fined by the Metropolitan Police, which issued 126 fixed-penalty notices for Covid breaches across Downing Street and Whitehall.