Conservative MPs need to accept the “uncomfortable truth” that Boris Johnson is a “liar” who must be booted out of Downing Street, according to Ian Blackford.
The SNP Westminster leader accused the Prime Minister of repeatedly lying over the partygate scandal and urged Conservatives in the Commons to remove him from office.
His claims came as the Commons considered a motion to instigate a parliamentary investigation into whether Mr Johnson lied to MPs about Downing Street parties during the coronavirus lockdowns.
Speaker Sir Lindsay Hoyle advised MPs to temper their language during the debate, although he did acknowledge they could “question the veracity” of Mr Johnson’s comments in the House given Labour’s motion cited specific dates.
But he added: “It is not in order to challenge more generally the truthfulness of the Prime Minister or any other honourable or right honourable member.
“Good temper, moderation must be maintained in parliamentary language.”
Mr Blackford was then judged to be in order as he accused the Prime Minister of being a liar while referring directly to concerns relating to statements on partygate.
Labelling an MP a liar in the chamber is usually considered unparliamentary language, although it is allowed when the House is considering a specific motion examining the conduct of a member.
Mr Blackford, who has previously been thrown out of the chamber for failing to withdraw claims against Mr Johnson, said in a message to Tory MPs: “The uncomfortable truth that the Prime Minister of the United Kingdom is a liar is exactly why they finally need to act and remove him from office.”
Earlier in his speech, he said: “At the very heart of this scandal there is one thing that needs to be said, one thing that needs to be heard and it’s the very reason that we all need to act.
“And the reason is this: the Prime Minister of the United Kingdom is a liar. I genuinely don’t say that lightly and I don’t say it loosely.
“I honestly believe that it’s right that we’re slow to use that word, but I equally believe that it is right that we should never be slow to say it and call it out when it is so obviously true.”
Mr Blackford added: “Last December, the Prime Minister came to this House and denied that there were any parties in 10 Downing Street during the long Covid lockdowns.
“Typically and tellingly, he hid behind his staff in saying it. He told us that he was given firm reassurance that no parties had happened and that no rules were broken.
“Every member of this Parliament witnessed it. The public saw it happen with their own eyes. And, shamefully, to this very day, it is still on the record of this House.
“But now we know the truth – and that truth contains no ifs, no buts and no maybes. The House was misled and so were the public – and we were all misled deliberately.
“Not only were parties happening, not only was the law broken, the Prime Minister was at the very parties he directly denied had even happened.
“The truth is simple and it’s this: he lied to avoid getting caught and once he got caught, he lied again. There is no other way to describe it. There is no other word for it.”
On Wednesday, SNP MP Richard Thomson (Gordon) was told to withdraw his claim that Mr Johnson was a “Pinocchio Prime Minister”.
Speaking earlier on Thursday at business questions, SNP Commons leader Pete Wishart said in relation to Mr Johnson: “We can’t even refer to a fictitious Disney character who is associated with the word that the public most use about him. They probably think we are just absolutely mad.”
Related: ‘The gig is up’: Senior Tory MP calls on Boris Johnson to resign
