Justice secretary Jack Straw has warned internet service providers (ISPs) he is planning to publish a consultative document on defamation on the internet.

The move follows mounting concern among the authorities over examples of claimed abuse, such as pupils mounting online attacks alleging malpractice by teachers and the difficulty the victims of libel face trying to sue their detractors.

Straw gave little indication of the direction his proposals will take when he gave evidence to the Commons Culture, Media and Sport Committee, but it is certain at least to consider how far ISPs can reasonably be held liable for content.