HOPES that a voluntary filter of child pornography will become industry standard across all internet service providers have been dealt a blow, with significant mid-sized carrier Internode declaring yesterday that it will not participate.

Communications Minister Stephen Conroy late last week announced the government would hold off on its filter proposal until a year-long review of refused classification rules had been completed.

At the same time the government said three internet service providers - Telstra, Optus and Primus, which between them represent about 70 per cent of Australian internet connections - would voluntarily block child abuse content, with the prospect that others might follow.