The High Court in London has ruled that bloggers have no right to privacy under British law, since "blogging is essentially a public rather than a private activity".

The case was brought by The Times after it discovered the identity of a blogger in the police service who wrote the popular NightJack blog, which was awarded the Orwell Prize for blogging in April.

The author, Richard Horton, a detective constable with Lancashire Constabulary, had sought an injunction to stop the newspaper releasing his name, but his application was denied.

"It would seem to be quite legitimate for the public to be told who was choosing to make, in some instances, quite serious criticisms of police activities and, if it be the case, that frequent infringements of police discipline regulations were taking place," said Mr Justice Eady, The Times reported.

"I do not accept that it is part of the court's function to protect police officers who are, or think they may be, acting in breach of police discipline regulations from coming to the attention of their superiors."

The NightJack blog was very popular with the reading public, getting up to half a million hits a week. Horton has now deleted the blog and received a written warning from his superiors.

The case will have a chilling effect on other workplace blogs, since the lack of any expectation of privacy will cause some to abandon their writing.

"Thousands of regular bloggers would be horrified to think that the law would do nothing to protect their anonymity if someone carried out the necessary detective work and sought to unmask them," said Hugh Tomlinson, QC, for Horton.

Police forces in the UK have supplied a number of authors of popular blogs, so much so that guidelines have been introduced aimed at limiting what can be said by officers on the beat.