Labour MP Dennis Skinner has been banned from the Commons for a day for comments about shadow chancellor George Osborne and cocaine.
Referring to the 1980s, Mr Skinner said: "The only thing that was growing then was the lines of coke in front of Boy George and the rest of the Tories."
Speaker Michael Martin told Mr Skinner to leave the chamber when he refused to withdraw the remark.
Mr Osborne later said it was "pretty desperate and personal stuff".
Mr Skinner, MP for Bolsover, also said, during Treasury questions, that coalfield areas would have "thanked their lucky stars" for the 1.75% growth now being forecast for this year by Chancellor Gordon Brown.
Mr Martin demanded he withdraw his claim but the veteran MP referred to Sunday newspaper claims - denied by Tatton MP Mr Osborne - that he had taken cocaine.
Mr Skinner said: "That was in the News of the World and you know it."
He continued to refuse when Mr Martin repeated his demand, saying: "No, I'm not withdrawing it ... it's true".
The speaker told him to withdraw the comment or leave the chamber, eventually saying: "I order you to leave the chamber."
Mr Martin added: "He's withdrawing, he's taken my advice... I know what I've done, he's moved and that's the main thing."
It was later confirmed that Mr Skinner would be excluded from the House for the rest of the day's sitting under rules about "grossly disorderly" behaviour.
He was not subject to an official "naming", which would have required a vote of MPs and meant a five-day suspension and loss of salary.
Speaking outside the chamber, a Conservative spokesman said: "When the Labour Party gets personal you know they are rattled.
"It is exactly this kind of behaviour that puts people off politics and which David Cameron's Conservative Party is trying to end."
'Beast of Bolsover'
Mr Osborne, appearing on BBC One's Question Time, said: "We were having a debate this morning on the economy, a huge issue of importance to everyone."
He added: "Dennis Skinner threw this abusive rant at me and he's on the front page of the newspapers."
The story was featured on the front of Thursday's London Evening Standard.
Mr Skinner has earned the nickname "the Beast of Bolsover" for his acerbic attacks on the Tories from his regular front row seat in the Commons chamber.
He has been upbraided in the Commons chamber before, and has been asked to leave nine times since 1979, including a five-day ban in 1981.
In 1992, he was thrown out for calling then Agriculture Minister John Gummer a "little squirt of a minister" and a "wart".
And he was banned for the rest of the day in 1995 when he accused ministers of a "crooked deal" to sell off the coal industry.