The Privileges Committee has condemned a number of Boris Johnson allies “who took it upon themselves to undermine procedures of the House of Commons” by criticising its inquiry into the ex-prime minister.
The committee highlighted comments by senior MPs including Nadine Dorries, Sir Jacob Rees-Mogg and Dame Priti Patel along with Lord Goldsmith – a serving minister.
The committee ultimately triggered Mr Johnson’s resignation from Parliament in protest at its recommendation that he should face a lengthy suspension for misleading the Commons with his denials of lockdown-busting parties in Downing Street.
The former prime minister's allies could now face suspension from Parliament, with Ministers expected to debate the findings of the report on July 10.
Mr Johnson's supporters frequently attacked the Tory-majority Privileges Committee as a “witch hunt” and “kangaroo court” – while the former prime minister was found to be complicit in the campaign against the panel investigating him.
Other MPs quoted in the report include Mark Jenkinson, Sir Michael Fabricant, Brendan Clarke-Smith and Andrea Jenkyns.
The report also highlighted the involvement of Lord Cruddas and Lord Greenhalgh, both given peerages by Mr Johnson, in a Conservative Post campaign putting pressure on the four Tory members of the committee to quit.
In the special report, the Privileges Committee named some of those involved and criticised their actions.
“Those Members did not choose to engage through any proper process such as the submission of letters or evidence to our inquiry, but by attacking the members of the committee, in order to influence their judgment,” the committee’s report said.
Their aim was to “influence the outcome of the inquiry”, “impede the work of the committee by inducing members to resign from it”, “discredit the committee’s conclusions if those conclusions were not what they wanted” and “discredit the committee as a whole”, it said.
The report added: “The committee is particularly concerned about attacks mounted by experienced colleagues, including a serving minister of the Crown, a former leader of the House and a former secretary of state for digital, culture, media and sport.”
The report said “pressure was applied particularly to Conservative members of the committee”.
Some MPs named in Thursday's report responded to the accusations on Twitter.
Mark Jenkinson wrote: "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."
Brendan Clarke-Smith tweeted: "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."
The report has 'the potential to have a chilling effect on free speech in parliament', says former Minister under Boris Johnson, Simon Clarke
Simon Clarke, a former minister in Mr Johnson's government, criticised the impact the report could have on MPs being able to freely speak their mind.
He said: "Today's report has the potential to have a chilling effect on free speech in parliament.
"As MPs, I believe we're accountable to the public who we serve, I don't believe we're accountable to each other.
"Once you start to say that certain people are effectively beyond criticism, with the exception of the Speaker, I think that really does place some MPs on the platform of being more equal than others."
'Here we are again, talking about the misbehaviour of Tory MPs' says Labour leader Sir Keir Starmer
Meanwhile, while on a visit to Selby, the Labour leader Sir Keir Starmer said the Privileges Committee's Partygate report was "further evidence of a divided party that is incapable of governing".
He added: "Rishi Sunak is simply too weak to deal with his MPs and you've got yet another story about misbehaviour by Tory MPs, and at the same time we're in the middle of a cost-of-living crisis.
"So, at the moment you want the Government to step it up, it's sitting it out, arguing about the behaviour of their own MPs, and this is one of the main causes of the fact that we're in this economic chaos now, and it's families that are paying the price."
After the report's release, House of Commons leader Penny Mourdant said MPs will debate the Committee's review on July 10.
A Downing Street spokesperson later said MPs would be granted a "free vote" when it comes to the Commons.
A free vote in the House of Commons is "unwhipped", meaning MPs aren't obliged to vote in line with what their party leader tells them to.
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