The retreat on the filter, which Labor proposed from early in its term, comes after a strong campaign by providers. Opponents argued it would not be effective, would be costly and slow down services, and involved too much censorship.

Communications Minister Stephen Conroy, who strongly argued the case for years, will announce on Friday that providers blocking the Interpol worst of the worst list ''will help keep children safe from abuse''.

''It meets community expectations, and fulfils the government's commitment to preventing Australian internet users from accessing child-abuse material online.''

The government will use its powers under the telecommunications legislation, so Senator Conroy will say a filter law will not be needed.

Senator Conroy says providers have been issued with notices requiring them to block illegal sites. ''This means that more than 90 per cent of Australians using internet services will have child-abuse material blocked'' by their provider.

Several Australian providers have already been blocking sites on the Interpol list for more than a year. They report there had been no impact on internet speeds of congestion, or of people being denied access to legitimate content.

Chief executive of the Internet Industry Association, Peter Lee, welcoming the government decision, says providers recognised their role in assisting law-enforcement agencies. Blocking the ''worst of'' list ''is a positive step in preventing Australian internet users from committing the offence of accessing child-abuse material''.

The Australian Federal Police will issue notices to smaller providers and will help them meet their obligations and prevent their services being used for illegal activities.

The Interpol process for identifying websites for the banned list is transparent. A site must be reviewed by authorities from two countries before it can be listed. Australian users trying to access banned sites will be redirected to a ''stop'' page.

The Australian Christian Lobby wants tougher action. On Thursday, it renewed its call for a mandatory filter.

This followed Perth's Hale School head of senior school Ross Barron saying students as young as 13 believe explicit sexual practices seen in online pornography are normal. He criticised parents for allowing unlimited access to the internet.

The Christian lobby says children as young as 11 are regularly accessing porn online. Research had also found that 84 per cent of boys and 60 per cent of girls had been exposed to internet sex sites accidentally.

The group says it recently made a submission to the Victorian Law Reform Committee's inquiry into sexting, calling on the federal government to introduce an internet filter. ''Currently, there is growing pressure for such a filter in the UK, with more than 110,000 people signing a petition calling for the government to enforce opt-in filters on online pornography.''