BBC News OnlineFirst minister's questions, which was to have followed the debate, had to be delayed for several minutes after a protest from the public gallery by a man wearing a George Bush mask.
BBC Scotland political correspondent Glenn Campbell said the man, Kevin Williamson, was better known for his protests about the use of cannabis and was the SSP spokesman on drugs.
Mr Williamson had been signed into the parliament by the SSP, whose MSPs clapped as he made his protest, our correspondent said.
When parliament resumed, Presiding Office George Reid rebuked the MSPs who had applauded the demonstration
He warned the Socialists that any future disruption would result in official action being taken.
First minister's questions, which was to have followed the debate, had to be delayed for several minutes after a protest from the public gallery by a man wearing a George Bush mask.