Google has voiced its opposition to a controversial law change that would force internet service providers to cut off "repeat copyright infringers, in appropriate circumstances".

In a submission to the Telecommunications Carriers Forum, an industry body, Google said section 92a of the Copyright Act would undermine the "incredible social and economic benefits" of the internet and was disproportionate to the problem it aimed to address.

TelstraClear appeared to deliver a death blow to the law change last week when it said it would not support the development of a code being drafted by the forum that attempted to set out how telcos could interpret their obligations under the act.

Spokesman Mathew Bolland said section 92a which is due to come into force on March 27 was a bad law that wouldn't work and had caused unprecedented customer concern.

Forum chief executive Ralph Chivers said TelstraClear's decision meant the forum could not formally ratify a code, since the industry body required unanimity from its members, which includes all the major telcos. But he said the forum would continue to work with its other members and the recording industry to flesh out an informal code that internet providers could adopt if they chose, should section 92a come into force. It would see copyright infringers disconnected after a series of warnings, with a possible right of appeal to an independent arbiter.

A spokesman for Commerce Minister Simon Power said the Government had been advised meaningful progress on a code was still being made. "If TelstraClear wants to be excluded from that arrangement, that is their choice." The Government reserved the right to look at the issue again.

Google accused the forum of dressing up its proposed enforcement scheme as an "education" exercise and said it was important that any code the forum came up with made it clear that there could be others ways for ISPs to comply with the law.

Sky Television said that ISPs should cut off copyright infringers sooner than the forum had proposed.