The Speaker of the House of Commons has permitted MPs to call Boris Johnson a "liar" during a parliamentary debate, breaking with recent convention.
The unusual step comes as parliament discusses whether the prime minister should face a standards probe for his conduct during the Partygate scandal – and over whether he misled parliament.
MPs are banned from using unparliamentary language in the chamber, which normally includes referring to other MPs as liars.
Speaker Lindsay Hoyle has sanctioned MPs for referring to the prime minister as a liar a number of times in recent months, ejecting SNP chief Ian Blackford from the Chamber in January and Labour MP Dawn Butler last summer.
But on Thursday he appeared to temporarily lift the ban, allowing Scottish national party MP Mr Blackford to repeatedly call Mr Johnson a liar.
"Not only were parties happening, not only was the law broken, the prime minister was at the very parties he denied had even happened! The truth is simple and it's this: he lied to avoid getting caught," Mr Blackford said in his contribution to the debate.
"And once he got caught, he lied again. There is no other way to describe it. There is no other word for it."
He added: "This is about the behaviour of a prime minister, and office, and much more importantly, the uncomfortable truth that the Prime Minister of the United Kingdom as a liar is exactly why they finally need to act and remove him from office."
As Mr Blackford told MPs again "that the prime minister of the United Kingdom is a liar" and that this was "so obviously true" there were murmurs of discontent from the government benches but no intervention from the Speaker
It comes after the prime minister was fined for attending a lockdown birthday birthday. The prime minister had initially claimed parties did not happen in Downing Street and then claimed he was furious to discover they had happened.
Clarifying the situation with language, the Speaker told MPs later in Mr Blackford's contribution: "It is about the terms of what we are debating."
Reading from a statement at the beginning of the debate on whether to refer Boris Johnson to the privileges committee for contempt of parliament, the Speaker Sir Lindsay had said: "While it is perfectly in order for the honourable members to question the veracity of the prime minister's responses to the House cited ion the motion it is not in order to challenge more generally the truthfulness of the prime minister or any other honourable member. Good temper must be maintained in parliamentary language."
Polling suggests the public agree that the prime minister lied about partygate: YouGov found that 7 per cent per cent of voters think he has lied about the episode, including 61 per cent of 2019 Tory voters and 51 per cent of those still saying they would vote Tory.
Meanwhile a survey by pollster JLPartners released at the weekend found that the prime minister is widely regarded as a “liar” more generally by the public, with the term the most cited when a representative sample of voters were asked to describe him.
