The ITV presenter backed up claims made by Boris Johnson’s former main aide Dominic Cummings. Both suggest a “very senior official” – in Mr Cummings’ words – told the top brass at Number 10 on May 20, in no uncertain terms, that the party should not go ahead.
Mr Peston wrote for ITV that Martin Reynolds, Mr Johnson’s PPS who invited around 100 staff to a “bring your own booze” party during the first national lockdown, was urged at the time to think again and cancel plans.
His email was reportedly copied to an official in the then-PPS’s office and to Mr Cummings.
Mr Reynolds “immediately” came to his office after he pressed “send”, according to Mr Peston, and asked why the party should be cancelled.
The sender told Mr Reynolds – “in the nicest possible way”, Mr Peston added – that, quite simply, it broke the rules.
Mr Reynolds is said to have responded that it could be more embarrassing to cancel the party than to go ahead with plans.
The official does not wish to be named because “he does not want to be seen as agent provocateur against the Prime Minister”, according to Mr Peston.
But the seasoned presenter said this testimony was “compelling”.
He wrote: “If it turns out he is lying he knows it will come out and he would be seriously damaged.”
READ MORE: Sturgeon’s Scotland shambles: Bin chaos hits city
Mr Cummings released a similar account of events released today.
He said the email from the “very senior official” will be seen by Sue Gray, who is leading an investigation into Covid rule-breaking at Number 10 – that is, “unless there is a foolish coverup which would also probably be a criminal offence”.
The official was not alone in raising a complaint, with Mr Cummings claiming he also told the PPS “the invite broke the rules”.
Mr Cummings wrote: “He [Mr Reynolds] said: so long as it’s socially distanced I think it’s OK, I’ll check with the PM if he’s happy for it to go ahead. (Obviously even if it was ‘socially distanced’ this would in no way make it ‘within the rules’.)”
EU sends team to Gibraltar days after Brexit warning [REPORT]
Brexit Britain marches on as M&S posts bumper Christmas numbers [REVEAL]
Boris warned his time is up thanks to ‘Blairite politics’ [OPINION]
Mr Reynolds said he would ask what the Prime Minister thought about the claim the party – what Mr Johnson has since claimed he believed was a “work event” – would fall outside of the rules.
Mr Cummings even told the Prime Minister himself, according to his version of events, that “you’ve got to grip this madhouse”, but Mr Johnson simply “waved it aside”.
All this, Mr Peston insisted, will act as invaluable evidence for Ms Gray in her ongoing investigation.
It will, he added, help her decide whether Mr Johnson broke lockdown rules on May 20 and whether he “committed the cardinal political sin of misleading Parliament”.
The Prime Minister has faced numerous calls to resign since he admitted to attending this party.
Perhaps the most significant of these came from Scottish Tory leader Douglas Ross, who said Mr Johnson’s position had become “untenable”.
Other senior Tories have been more reluctant to fall on one side of the divide or the other, preferring to wait to hear Ms Gray’s verdict.