Rishi Sunak will likely be challenged over Tory infighting in his weekly clash with Sir Keir Starmer, following his public spat with Boris Johnson over his predecessor’s resignation honours list.
The Prime Minister will also move closer to two difficult by-elections, including in the seat vacated by Mr Johnson, when the Conservatives give notice for the contests on Wednesday.
The war of words between the current and former prime ministers erupted after Downing Street published Mr Johnson’s honours list on Friday, lacking the names of sitting MPs including former culture secretary Nadine Dorries and former minister Nigel Adams.
Hours later Mr Johnson dramatically announced his Commons exit, as the Privileges Committee prepared to report that he lied to Parliament over partygate.
Loyalists Ms Dorries and Mr Adams also said they were standing down as MPs.
The Prime Minister suggested his former boss wanted him to ignore the recommendations of the House of Lords Appointments Commission.
Mr Johnson said he was talking “rubbish” and his camp accused Mr Sunak of having “secretly blocked” the peerages of Ms Dorries and other allies.
Labour leader Sir Keir has warned that the row between the two erstwhile allies was damaging the UK’s reputation internationally.
He said the three by-elections triggered by Mr Johnson, Ms Dorries and Nigel Adams were effectively “political tantrums”.
Chief Whip Simon Hart is expected to move a motion known as a “writ” for by-elections in Mr Johnson’s Uxbridge and South Ruislip constituency and Mr Adams’ Selby and Ainsty seat on Wednesday, giving between 21 and 27 working days for votes to be held.
But the third by-election in Ms Dorries’ Mid Bedfordshire constituency is on hold because she has not formally resigned as a Tory MP.
It comes despite the former Cabinet minister, who accused Mr Sunak of “duplicitously and cruelly” blocking her elevation to the House of Lords, on Friday saying she would be standing down with immediate effect.
Her delay in formally quitting hampers the Tories’ objective to limit the political fallout by holding all three contests on the same day, as the party trails in the polls.
Meanwhile, Westminster is bracing for the Privileges Committee’s report which is expected to find that Mr Johnson deliberately misled MPs with his assurances that lockdown rules were followed in Downing Street.
The former premier, who received a draft of the findings before quitting, urged the panel to publish its “nonsense” after a delay in the publication caused at least in part by his last-minute representations to the committee.
The release had already been pushed back towards the end of this week, reportedly due to printing problems in Parliament, before Mr Johnson’s 11th-hour submission to the panel at 11.57pm on Monday.