Labour MP Dawn Butler has been ordered to leave the Commons chamber after she refused to withdraw accusations that Boris Johnson is a liar.
Ms Butler said the prime minister had “lied to the House and the country over and over again”.
Under parliamentary rules, MPs are not allowed to accuse each other of lying in the House of Commons.
The acting Deputy Speaker asked the MP to withdraw her remarks but Ms Butler refused and was ordered to leave.
The incident took place during the final debate in the House of Commons before MPs leave Westminster for the summer.
Ms Butler used her speech to attack the prime minister for “misleading this House” during the pandemic.
The Brent Central MP cited past statements on economic growth, nurses’ bursaries and investment in the NHS as proof of the prime minister’s dishonesty.
The rules governing behaviour in the Commons state that MPs are not allowed to use abusive language or accuse another MP of either being drunk or a liar.
Acting Deputy Speaker Judith Cummins interrupted Ms Butler and asked her to “reflect on her words and perhaps correct the record”.
Ms Butler replied: “At the end of the day, the prime minister has lied to this House time and time again and it’s funny that we get in trouble in this place for calling out the lie, rather than the person lying.”
Ms Cummins again urged the MP to take back her comments but Ms Butler said, “I have reflected on my words and somebody needs to tell the truth in this House that the prime minister has lied.”
The Deputy Speaker then ordered Ms Butler to withdraw from the Commons for the rest of the day’s sitting.
Downing Street has been contacted for a comment.