Hundreds of requests by British intelligence agencies to monitor people's email and web traffic are made every year, but each is judged by a strict legal code, British foreign secretary William Hague told MPs yesterday.
Each application to the foreign secretary or home secretary must set out the limits of the surveillance, along with “the potential risks and the intended benefits of the intelligence”, complete with “comprehensive legal advice”, he said.
Each warrant has to be individually signed by a senior minister, he told the Commons during an emergency debate.
"This is no casual process. Every decision is based on extensive legal and policy advice.
Carefully targeted
"Warrants are legally required to be necessary, proportionate and carefully targeted, and we judge them on that basis. Considerations of privacy are also at the forefront of our minds as I believe they will have been in the minds of our predecessors," he said.
Warrants issued are later subjected to inspection by two former senior judges who report directly to the prime minister and who must be satisfied that the ministers’ actions “are fully compliant with the law”.
Saying that the intelligence agencies’ successes can never be recorded, Mr Hague dropped strong hints that co-operation with the Americans foiled terrorist plans to target last year’s London Olympics. The UK-US relationship “has been and remains essential to the security of both nations, has stopped many terrorist and espionage plots against this country, and has saved many lives”, said Mr Hague.
Today senior figures from the Commons' intelligence and security committee, led by former Conservative minister Sir Malcolm Rifkind, will meet in Washington with both the National Security Agency and the Central Intelligence Agency for meetings planned long before Prism was revealed.
Former Labour home secretary Jack Straw said: "Many of our allies, leaving aside the United States, are astonished by the degree of control and supervision of our system" which "surpasses most other western democracies".
7Intelligence agencies “face an impossible dilemma”, said Mr Straw as he strongly backed Mr Hague.
"When things are relatively calm then suspicions, fantasies, even paranoia can take off about the so-called secret state."
'Turn on a six pence'
However, the opinions of newspapers and surveillance opponents will "turn on a sixpence" the moment a terrorist attack occurs, where they demand why there was "a failure of those agencies to track through intelligence of all kinds the miscreants involved".
In his speech Mr Hague rejected charges that the British government’s listening station in Cheltenham, GCHQ, used the US National Security Agency to carry out surveillance on UK citizens that it cannot itself do legally.
“I wish to be absolutely clear that this accusation is baseless. Any data obtained by us from the US involving UK nationals is subject to proper UK statutory controls and safeguards.”
