Boris Johnson said it is “concerning” that the inquiry into whether he lied to MPs will rely on evidence by partygate investigator Sue Gray as she will be working for Labour.
But the Privileges Committee defended its probe, saying it is “not based on the Sue Gray report”, which last year detailed lockdown-breaking, booze-fuelled parties in Downing Street during Mr Johnson’s leadership.
The former prime minister and his allies have used Ms Gray’s planned move to Sir Keir Starmer’s office to try to discredit the cross-party panel’s inquiry into whether he lied to the House of Commons over lockdown breaches.
The committee’s report is not based on the Sue Gray report— Privileges Committee
In a statement, Mr Johnson said: “It is surreal to discover that the committee proposes to rely on evidence culled and orchestrated by Sue Gray, who has just been appointed chief of staff to the leader of the Labour Party.
“This is particularly concerning given that the committee says it is proposing to rely on ‘the findings in the second permanent secretary’s report’ as ‘relevant facts which the committee will take into account’.”
He later told broadcasters people may now look at the Gray inquiry in a “different light”.
“If you told me at the time I commissioned Sue Gray to do the inquiry, if you told me all the stuff that I now know, I think I might have cross-examined her more closely about her independence,” he added.
“I might have invited her to reflect on whether she was really the right person to do it.”
However, the committee rejected the claims, saying its inquiry is based on evidence including witnesses, WhatsApps, emails and images from a Downing Street photographer.
Arch loyalists of Rishi Sunak’s predecessor in No 10 have reacted furiously to the move by the senior civil servant who carried out the probe which played a role in Mr Johnson’s downfall.
Nadine Dorries, the former culture secretary, said: “Sue Gray’s evidence cannot be relied upon in any meaningful way until we know how long Sue Gray has had a personal relationship with Keir Starmer and for how long they have been discussing Sue going to work for him as his most trusted and important adviser.”
A well-placed ally of Mr Johnson said the committee’s inquiry is “beyond a farce and totally lacks credibility”, while Tory MP Mark Jenkinson called it a “total circus”.
Labour dismissed claims that Ms Gray’s move to Sir Keir’s office proved a plot to oust the former prime minister as “ludicrous”.
The Labour leader said Mr Johnson “needs to confront the evidence that is there in front of him and everybody can see that evidence” rather than dispute Ms Gray’s integrity.
Shadow culture secretary Lucy Powell said Mr Johnson is using the appointment to “vindicate himself further” after he was ousted over a series of scandals.
Ms Gray will take up the role of Sir Keir’s chief of staff after following the “normal procedures”, which could include a recommended waiting period ultimately decided by Mr Sunak.
She is expected to await the decision of the Advisory Committee on Business Appointments (Acoba) before starting the role.
Parliament’s anti-corruption watchdog can advise waiting periods before civil servants take on other jobs and the Prime Minister ultimately makes the final decision.
But Downing Street made it clear that Mr Sunak cannot block her from taking a job.
Mr Johnson received one of the 126 fines issued by the Metropolitan Police while the force investigated lockdown-busting parties in Downing Street and Whitehall.
Ms Gray got the job as partygate enforcer after Cabinet Secretary Simon Case had to step down from the investigation when he became embroiled in claims of partying during the pandemic.
Published last May, her investigation detailed how officials drank so much they were sick, sang karaoke, became involved in altercations and abused security and cleaning staff.
She criticised “failures of leadership and judgment” in No 10 and said “the senior leadership at the centre, both political and official, must bear responsibility”.
The Cabinet Office was “reviewing the circumstances” under which Ms Gray resigned on Thursday.
Jacob Rees-Mogg, a staunch Johnson ally, defended his former boss on Friday as he questioned the appropriateness of Ms Gray moving to her new role.
“Going from such a senior role to being the key adviser to the leader of the Opposition, with all the Government secrets that you will have – bear in mind she was in charge of ethics for the Government.
“She will have known ministers’ most personal details.
“It seems to me that she is not the right person to be going into a party political role,” the former cabinet minister told Channel 4 News.
But Sir Jonathan Jones QC, the former head of the Government’s legal department, added his voice to those defending Ms Gray.
He told BBC Radio 4 that her move to a political role “doesn’t in any way contaminate the outstanding work she’s done as a civil servant, including this really difficult task which Mr Johnson himself asked her to do”.
