The row over using surveillance information to spy on people has intensified after it was revealed that 1,400 requests to snoop on the public were made every day last year.
Councils, police and the intelligence services asked more than 500,000 times for approval to access private email and phone data.
Each one allows public authorities access to communications data - which includes records of phone, email and text messages - but not their content.
The Home Office says the new figures "offer reassurance that the powers are being used appropriately".
But the Liberal Democrats' home affairs spokesman Chris Huhne said the figures "beggared belief" and the country has "sleepwalked into a surveillance state".
"It cannot be a justified response to the problems we face in this country that the state is spying on half a million people a year.
"The Government forgets that George Orwell's 1984 was a warning, and not a blueprint."
The figures were published in the annual report of the Interception of Communications Commissioner, Sir Paul Kennedy.
It showed 504,073 requests for communication data were made last year, or nearly 10,000 every week.
Although slightly down on last year, the total is up more than 40% on two years ago.
A Home Office spokesman said: "Of course it's vital that we strike the right balance between individual privacy and collective security.
"And that is why the Home Office is clear these powers should only be used when they are proportionate." (Sky News, 8.10.2009) http://news.sky.com/skynews/Home/UK-News/Spying-On-Public-1500-Requests-Made-Every-Day-Last-Year-For-Surveillance-Information/Article/200908215357406?lpos=UK_News_Third_UK_News_Article_Teaser_Region__0&lid=ARTICLE_15357406_Spying_On_Public%3A_1%2C500_Requests_Made_Every_Day_Last_Year_For_Surveillance_Information