Councils, police and the intelligence services asked more than 500,000 times for approval to access private email and phone data, official figures revealed.

The total number of requests - including 1,500 from local councils - were approved. Each one allows public authorities access to communications data - which includes records of phone, email and text messages - but not their content.

The Liberal Democrats’ home affairs spokesman Chris Huhne said the figures “beggared belief”, and questioned whether so many operations were necessary.

He said: “Many of these operations carried out by the police and security services are necessary, but the sheer numbers are daunting.

“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.

“We have sleepwalked into a surveillance state but without adequate safeguards. Having the Home Secretary in charge of authorisation is like asking the fox to guard the hen house.

“The Government forgets that George Orwell’s 1984 was a warning, and not a blueprint. We are still a long way from living under the Stasi but it beggars belief that it is necessary to spy on one in every 78 adults.

“The fact that numbers are up a half on two years ago makes a mockery of the Government’s supposed crackdown.”

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.

Over the last three years, 1.2million requests were made - the equivalent of one for every 31 adults in the UK. Last year details handed over contained nearly 600 errors.

Powers to ask for the private data were handed to town halls and other government agencies under the controversial Regulation of Investigatory Powers Act (RIPA).

Revelations that council officials used RIPA to snoop on people accused of letting their dogs foul the pavement, or leaving their bins out early provoked outrage and ministers have launched a review of its use.

A Home Office spokesman said the powers should be used only when they are “proportionate”.

He said: “The report shows requests for communications data were down on last year.

“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.

“To ensure the appropriate use of RIPA the Home Office has recently completed a public consultation on revised Codes of Practice, and on all public authorities able to use certain techniques relating to RIPA, the ranks at which these techniques can be authorised and the purposes for which they can be used.”

Shadow home office minister James Brokenshire said: “This report underlines public concerns about the scope and breadth of snooping powers.

“Trust and confidence in the use of surveillance is being eroded by their disproportionate use.

“It is astounding that the Home Office should be considering expanding the rights of public agencies to obtain even more of our email and communications data without addressing these fundamental issues.

“Conservatives will protect the rights of law-abiding citizens from Labour’s growing ‘snooper’ state.

“That’s why we would change the law to end abuse of powers which should only be used to tackle terror and serious crimes.”