Mr Cummings said the Prime Minister lied over allegations of bashes in Downing Street as the rest of the country observed strict social distancing rules. He insisted he told the PM to get a grip on the “madhouse” when warning him about one “drinks party”.
The ex-chief adviser said on Monday Mr Johnson waved it aside when he raised concerns over Principal Private Secretary (PPS) Martin Reynolds inviting more than 100 people to a “bring your own booze” event in the No.10 garden on May 20, 2020.
In response to Mr Cummings’s intervention, the FT’s Chief Political Correspondent Jim Pickard tweeted: “[T]here’s something objectively hilarious about the Barnard Castle guy rooting out breaches of [C]OVID-19 lockdown rules.”
To which fellow Twitter user Bonnie_Chuck replied: “Eyesight test worked. With a new and clearer vision, he was able to better see the breaches.”
In May 2020, Mr Cummings said in a statement in Downing Street’s rose garden that he drove to Durham in March – when the country was in lockdown – to stay at his father’s property after his wife fell ill.
The political strategist added that he then drove to Barnard Castle to test his eyesight after experiencing loss of vision due to coronavirus before he made the return journey to London.
A year later, Mr Cummings explained that security threats made against his family had also formed part of the reason for the trip to Durham.
The Twitter remarks come after Mr Cummings updated a blog-post on Monday in which he said that he warned Mr Reynolds his emailed invite to staff broke the rules.
He wrote: “Amid discussion over the future of the Cabinet Secretary and PPS himself, which had been going on for days, I said to the PM something like: ‘Martin’s invited the building to a drinks party, this is what I’m talking about, you’ve got to grip this madhouse’.
READ MORE ON THREE OIL TANKERS EXPLODING IN AN IRAN-BACKED REBEL ATTACK
The SNP’s leader at Westminster Ian Blackford said Mr Cummings was a key witness and called for him to be interviewed as part of senior civil servant Sue Gray’s probe into parties held at No.10 during England’s coronavirus lockdown.
He said: “The Prime Minister’s former chief adviser, who was in post at the time Boris Johnson broke the law, has said he is willing to testify on oath that the Prime Minister was warned about the Downing Street party, allowed it to go ahead anyway, attended it himself, and then lied to Parliament.
“Lying to Parliament would be a clear breach of the ministerial code alone and would require the Prime Minister to resign immediately.
“That makes Mr Cummings a key witness in Sue Gray’s inquiry. Without his account, the inquiry will not be worth the paper it is written on.
“The Prime Minister must now confirm that Sue Gray will interview Dominic Cummings as part of her investigation.
“Mr Johnson must then come to Parliament and put on record whether he believes Mr Cummings is lying, or whether he will finally admit that he has repeatedly lied to Parliament and the people himself.”
A No.10 spokesman said in response to Mr Cummings’s claim: “It is untrue that the Prime Minister was warned about the event in advance. As he said earlier this week he believed implicitly that this was a work event.
“He has apologised to the House and is committed to making a further statement once the investigation concludes.”