Dennis Skinner has been barred from the House of Commons for the rest of the day after accusing shadow chancellor George Osborne of taking drugs.
The Labour MP for Bolsover, who first entered parliament 35 years ago, turned on the Conservative spokesman during Treasury questions this morning.
Referring to employment under the Conservatives in the 1980s, he declared: "The only thing that was growing then were the lines of coke in front of boy George and the rest of the Tories."
Commons speaker Michael Martin asked the MP to withdraw his remarks, but Mr Skinner shouted: "No, I'm not withdrawing it. it's true."
Mr Martin repeated his demand, and then ordered the Labour member to leave the chamber. It has since been confirmed that he has been banned for the rest of the day.
Mr Skinner was referring to photographs published in the News of the World which allegedly showed a young Mr Osborne talking to a prostitute, with what she said was a line of cocaine.
The photographs were published as the tabloid press attempted to dig up dirt on David Cameron during the Tory leadership race. Mr Cameron, who has since been named the new party leader, had refused to confirm or deny whether he had taken class-A drugs.
This is not the first time Mr Skinner, a former miner, has been disciplined in the Commons. He has been asked to leave nine times since 1979, for incidents which included calling then agriculture minister John Gummer a "wart".
Nor has he ever shrunk from abusing his political opponents outside the protection of the chamber - in a speech to the Labour party conference in Brighton, he condemned the Lib Dems for having a "focus leaflet for every street".
And he dismissed Tory leadership candidate David Davis as having a life worthy of a Jeffrey Archer novel, and Ken Clarke of spending all his time "out in the third world selling fags".