Prime Minister Tony Blair's authority was thrown into doubt Wednesday after his attempt to toughen up Britain's antiterror laws in the wake of the London bombings was roundly defeated in parliament.

It was the first time in his eight years in power that Blair had been humiliated in the House of Commons, with no less than 49 members of his own Labour Party joining the opposition to water down the Terrorism Bill.

Speculation immediately swirled over how long Blair will be able to act effectively, or even how long he can stay in office, particularly with controversial health and education reforms in the pipeline.