The Internet Service Providers Association (ISPA) has said it is "outraged" after the House of Lords voted through Amendment 120A to the U.K.'s Digital Economy Bill. It would allow the High Court to grant an injunction requiring ISPs to block Web sites with a "substantial proportion" of copyright-infringing content.

The opposition amendment replaces the unpopular Clause 17, which would have given the government substantial powers to amend the law to deal with any future piracy threat.

U.K. music industry trade body the BPI has welcomed the move, but ISPs have been unhappy with measures contained in the Bill.

In particular, ISAP said in a statement that clause 17 "has been hastily constructed and rushed through at report stage without due consideration of the implications or consultation with the interested parties that would be affected."

The ISPs' trade body added that legal, technical and practical issues have "not been debated in nearly enough depth" and that this was "negligent."

The courts already have powers to grant an injunction requiring ISPs to block access to sites that contain unlawful copyright content, but ISPA said this amendment introduces a "bias in favor" of rights holders and limits the court's discretion to judge each case on its merits.

"ISPA has been supportive of Peers' excellent scrutiny of the Bill to date," said ISPA secretary general Nicholas Lansman in a statement. "However, in this instance, our members are extremely concerned that the full implications of the amendment have not been understood and that the reasoning behind the amendment is wholly misguided. We would therefore urge the Conservatives and Liberal Democrats to urgently reconsider their position."

A third day of the report stage on the Bill will take place at the House of Lords on March 8.