People trying to view the 2001 electoral roll at libraries have been told: "You can't - but you can look at the old one."

The strange new rule has left many people bemused.

After the electoral roll for 2001 was published just before Christmas, some councils decided not to place it in local libraries following advice from the Electoral Commission.

The commission warned local authorities not to sell data from the roll after a test case under European human rights law in November.

Previously, councils were legally obliged to make information - which includes names and addresses of voters - available to commercial companies for £18 per 1,000 names.

But judges ruled selling data to companies for purposes such as junk mailing breached human rights.

And some councils have taken the Electoral Commission's advice to mean even public libraries should not be given copies.

Electoral rolls from previous years are still available to library users because they are already in the public and commercial domain.

Worthing, Adur and Arun councils have not put the new electoral roll in libraries, but Brighton and Hove City Council has.

A Brighton and Hove City Council spokeswoman said: "We have taken the advice to mean we can't sell the electoral roll and no more. It is still available in libraries."

A spokesman for Worthing Borough Council admitted the Electoral Commission advice did not mention libraries but added: "If we provide it to libraries it is accessible to commercial companies."

An Electoral Commission spokeswoman said: "Our guidance doesn't have any bearing on libraries.

"The electoral roll is still a public document and people can still go along to certain libraries to view it."