The about-turn was criticised by the Conservatives, who accused the party of having shown itself yet again to be "soft" on terrorism.
But Lembit Opik, who spoke in support of the emergency motion at the party's conference, denied there had been a policy change, stressing that the vote reaffirmed the Liberal Democrats' commitment to replace the existing Criminal Justice (Terrorism and Conspiracy) Act with a comprehensive legislative package.
"It is irresponsible of the Tories to suggest otherwise," he said. The draconian measures, which were passed amid the terrorist atrocities of Omagh, Nairobi and Dar es Salaam, make it easier to secure convictions of proscribed members of terrorist organisations, such as the Real IRA, by allowing the evidence of senior police officers to be submitted to courts.
It also makes it a criminal offence to conspire to commit a criminal act abroad. Mr Opik, the Ulster-born son of Estonian refugees who fled Stalin's troops in the Second World War, said he spent eight years fighting for the independence of Estonia by attending demonstrations against the Soviet regime in Britain, a protest which would be illegal under the Bill.
He said that the parliamentary party had voted for the legislation because it was needed to move forward the peace process in Northern Ireland.
However, he attacked the clauses of the Act dealing with the international dimension, saying: "We did the right thing and we made it clear that we opposed the clauses to combat international terrorism. We will not beholden to the media circus of Tony Blair."