On Thursday, the Commons committee that looked into Boris Johnson's involvement in Partygate is anticipated to criticize his allies.
The Privileges Committee found that the former prime minister had lied to Parliament regarding Covid violations in No. 10 and ordered him to resign as a member of Parliament.
A number of his backers criticized the committee's year-long investigation.
It stated that there was a "sustained attempt" to "undermine" the credibility of its members.
In their report on Mr. Johnson, they stated that the criticism of their work might make it "impossible" for future sensitive investigations to be conducted in a similar manner.
Former cabinet minister Nadine Dorries, a supporter of Mr. Johnson, has also criticized the committee and referred to it as a "kangaroo court" on television.
Seven people make up the cross-party committee, including two Scottish National Party members, two Labour members, and four Conservative MPs.
Mr. Johnson should have received a 90-day suspension if he had continued to serve as an MP, according to the investigation's findings, which were made public in April.
Before the committee's final report was released, Mr. Johnson decided to resign. In a scathing resignation statement, he called the committee a "kangaroo court.".
The BBC has been informed that the reader will be left with no doubt as to which MPs the committee is criticizing in tomorrow's report.
Some MPs privately believe it is ridiculous that there should be some kind of restriction on what they can say in public regarding a committee of their peers looking into a colleague.
It is absurd that this committee is acting like a court of law when it is obviously not, one person told the BBC.
The rules governing the Privileges Committee's inquiries could not be changed until Parliament approved any conclusions or recommendations made by the committee.