LONDON, March 7: Britain's House of Lords voted on Monday to force changes on Prime Minister Tony Blair's controversial anti-terror laws, creating a stand off between the government and parliament's un elected upper chamber.

Mr Blair backed down once last week, conceding that any 'control order' to place a terror suspect under house arrest would require the approval of a judge. Until then, he had insisted that power should rest with ministers alone. But the Lords voted by 249 to 119 on Monday that all such orders - ranging from electronic tagging to curfews and freedom of association - should go before a judge. They also demanded a higher standard of proof before any restrictions of movement could be imposed.

"They have to be better than the awfulness of what is in this bill," Helena Kennedy, a senior lawyer and peer in Mr Blair's Labour party, said of the amendments. Ministers must now decide whether to accept the changes or risk losing the bill entirely.

Mr Blair is seeking to push the legislation through parliament by March 14, when current anti-terrorism powers allowing indefinite detention of foreign terror suspects expire. Britain's highest court ruled late last year that those measures infringed basic rights and should be scrapped.

The government seized upon weekend comments by Sir John Stevens, just retired as chief of London's Metropolitan Police, who said more than 100 "Osama bin Laden-trained terrorists" are on the streets of Britain, determined to carry out mass attacks.

The prime minister can also take comfort from polls that show public opinion is on his side. He will accuse his Conservative and Liberal Democrat opponents of being soft on terrorism if they block the bill.

Mr Blair's official spokesman suggested no further compromises would be forthcoming, stressing the premier's determination 'to get the legislation through'. But parliamentary opposition to the bill in both the Lords and the elected House of Commons is sizable. -Reuters