After an unprecedented stand-off between its two houses, Britain's parliament finally passed Prime Minister Tony Blair's controversial anti-terrorism bill into law on Friday. Peers in the unelected House of Lords, having rejected the bill throughout this week, including an all-night debate on Thursday, acquiesced after Blair promised there would be an opportunity to amend the legislation fundamentally next year. His opponents had demanded that the law, which allows for tough measures up to and including house arrest for suspected terrorists, to lapse automatically. Blair's leader in the upper chamber, Lord Falconer, said the parliamentary sitting, which began on Thursday morning had been the longest on record -- at over 30 hours. --SP 2219 Local Time 1919 GMT