Commons Speaker Lindsay Hoyle has written to MPs warning them not to initimidate the Boris Johnson Partygate inquiry.
In an email, seen by the Independent, Speaker Hoyle tells them: “A very dim view will be taken of any Member who tries to prevent the Committee from carrying out this serious work, or of anyone from outside the House who interferes.”
He adds: “The Committee must be allowed to complete its work without interference, both in relation to the evidence it is taking today and during the time before its report is published.
“I would like to remind you that interference with or intimidation of a committee is potentially a contempt of the House and restraint is appropriate while the Committee’s work continues.”
The email was sent this morning just hours before Boris Johnson is due to appear before the parliamentary investigation into parties in Downing Street during Covid.
Fighting for his political life, the ex-PM has admitted he misled parliament about rule-breaking but insisted his denials were "in good faith".
Mr Johnson’s allies have been accused of trying to "bully" and intimidate the committee probing Partygate ahead of his showdown televised grilling later.
Senior Conservatives have joined Labour in urging the Johnson camp to stop "disgraceful" efforts to undermine the privileges committee - warning that it "borders on contempt of parliament".
His supporters have repeatedly lashed out at the inquiry - calling it a "McCarthyite witchhunt" and pressuring four Tory MPs on the cross-party committee to quit.
Writing for The Independent, former Tory attorney general Dominic Grieve said the group of eight MPs would act impartially and "should not be deflected from irrelevant bluster" by the Johnson camp.
The ex-Tory leader's close ally Conor Burns, a former Northern Ireland minister, has questioned the impartiality of the chair of the committee Harriet Harman, suggesting she had "predetermined" views.
It follows Conservative Post - a website affiliated with Lord Cruddas' Conservative Democratic Organisation (CDO) - calling on party members to email the four Tory MPs who sit on the committee and urge them to quit the "banana republic" inquiry.
One senior Conservative MP accused Mr Johnson’s allies of trying to "bully" the committee in a way that "borders on contempt of parliament".
The Rishi Sunak backer told The Independent: "To seek to interfere with due process - to try to cheat the process - is a serious issue. It could backfire when it comes to MPs and the mood to punish him. If you keep making this out to be a kangaroo court, it shows you just don't get it."
Tory MP Nigel Mills said: "It smacks of desperation. They're attacking the referee before kick-off."
Tobias Ellwood, chair of the defence select committee, told The Independent that the committee would not be "dazzled or distracted", warning Mr Johnson and his allies: "Any sign of impropriety will paint all of parliament in a poor light."
