Ex-Downing Street staff are reportedly set to give evidence which will claim Boris Johnson did mislead Parliament over the partygate scandal.
According to three former staff members, Johnson did not give a full account of the facts he knew about the illegal gatherings held at Number 10, it is reported.
The staff have been contacted by a committee investigating what the PM knew, and one has agreed to give evidence - while another two are considering following suit, reports The Telegraph.
It is the clearest indication of what Harriet Harman, the Labour chairman of the Privileges Committee, has gathered as part of her investigation.
One of those being asked to give evidence said: “On the facts, he was definitely at lockdown-breaking events and he knew they were happening and therefore what he said to the House was knowingly inaccurate.”
The probe is aiming to discover if lockdown-breaking parties in Downing Street first emerged, amounted to contempt of the House of Commons.
As partygate game to light, Boris Johnson claimed saying “no Covid rules were broken” and “all guidance was followed in No 10”.
However, a police probe led to dozens of fines being issued to Number 10 staff over Covid law-breaking in government buildings.
Last month, Boris Johnson was today ordered to hand a vast cache of evidence to the probe into whether he lied to Parliament over Partygate.
The Privileges Committee demanded diaries for the eight days he attended Covid lockdown-busting gatherings in Downing Street - which led to more than 100 fines from police.
MPs also ordered photos, internal notes, the PM’s briefing packs, e-mails, resignation statements and door logs - and warned the list could be expanded further at a later date.
Harriet Harman set an August 15 deadline for No10 to serve up the documents - before Boris Johnson hands his resignation to the Queen on September 6.
And she ordered the nation’s top civil servant to let her committee visit 10 Downing Street, to “inspect” where the parties happened.
Ms Harman stressed she was not seeking to “attribute blame” to staff or former staff. She added witnesses who “wish to remain anonymous” can give evidence about whether the Prime Minister lied.
Seven MPs, including four Tories, are probing the PM’s claims that “the rules were followed at all times” and he was “repeatedly assured there was no party".
Mr Johnson's allies have moaned the probe will be a "kangaroo court" and it will continue despite a new Tory leader being unveiled on September 5.
Hearings with witnesses - who could include the PM and wife Carrie - are due to begin in September and insiders believe the committee will not report back until October or November at the earliest.
Boris Johnson could avoid any sanction from the committee if he chose to quit as an MP.
