The Government was accused last night of hoarding information about people who pose no danger to this country, after it emerged that MI5 holds secret files on 272,000 individuals - a staggering one in 160 adults.

MPs and civil-rights campaigners said resources should be concentrated on combating genuine threats - such as Islamic terrorism - rather than storing personal and political data about innocent citizens.

Figures released by the Home Office last week reveal that another 53,000 files are held about organisations, but 110,000 files have been destroyed since Labour came to power in 1997.

The information was obtained by Liberal Democrat MP Norman Baker, who believes he was the target of MI5 surveillance in the Eighties because of his activities as an environmental protester.

Five years ago he won a High Court ruling giving him access to his file, which ended the security services' blanket exemption from the Data Protection Act.

Last night, Mr Baker said: 'I don't believe there are 272,000 people in this country who are subversive or potentially subversive. It suggests to me that there are files being held for not very good reasons.