The Home Office is asking internet service providers (ISPs) to keep records of which websites their customers visit, what newsgroup articles they read and who they email for 12 months. The move is part of new anti-terrorist legislation proposed by Home Secretary David Blunkett.

It will include "measures to enable communication service providers to retain data generated in the course of their business, namely the records of calls made and other data - not the content".

Home Office officials said that the Government will work with the industry on a code of practice to take this forward. No other details have been provided, but campaigners fear that the Government may yet make such log-keeping compulsory.

They are also concerned that, combined with powers granted under the Regulation of Investigatory Powers Act, the legislation will provide law enforcement agencies with a licence to snoop on activists.

Caspar Bowden, director of the Foundation for Information Policy Research, warned: "Sensitive data ... could be collected in the name of national security. But Mr Blunkett intends to allow access to this data for purposes which have nothing to do with fighting terrorism.

"Minor crimes, public order and tax offences, attendance at demonstrations, even 'health and safety' will be legitimate reasons to siphon sensitive details of private life into government databases to be retained indefinitely."

ISPs have been retaining records since 11 September at the Home Office's request, and last week indicated to vnunet.com's sister publication Computing their willingness to hold records for up to three months. However, they have long been opposed to the retention of logs for any significant period of time.

Data records retention has also split Brussels, with European Union ministers and European Commission officials adopting opposing positions.

EU ministers are backing law enforcement authorities' demands to extend laws to aid criminal investigations, while the EC supports the position of civil rights groups and carriers/ISPs, which have argued that current laws suffice and that the proposed extensions go much too far.