Britain’s spymasters are facing an unprecedented televised grilling at the hands of MPs.
For the first time the heads of the Secret Intelligence Service, MI6, the Security Service, MI5, and the electronic eavesdropping agency, GCHQ, will today line up together to give evidence in public to the parliamentary Intelligence and Security Committee (ISC).
Sir John Sawers, the chief of MI6, Andrew Parker, the director general of MI5, and Sir Iain Lobban, the director of GCHQ, will take a rare step out of the shadows to answer questions about the work of their organisations.
Their appearance at Westminster comes amid intense debate over the role of the agencies following the disclosures by the former US intelligence operative, Edward Snowden, of the surveillance activities of GCHQ and its American counterpart, the National Security Agency (NSA).
Documents leaked by Mr Snowden - who is currently in Moscow where he has sought sanctuary from the US authorities - have shown the agencies are able to tap into the internet communications of millions of ordinary citizens through GCHQ's Tempora programme while the NSA has bugged the phone calls of dozens of world leaders.
While the disclosures have alarmed civil liberties activists and created tensions with allies, Government ministers and officials have warned that by exposing the agencies’ methods, they were jeopardising security. Mr Parker has described them as a “gift” to terrorists.
In the latest case, the British ambassador in Berlin was this week called in to the German foreign ministry to explain reports that GCHQ was operating a secret listening post on the roof of the embassy within a stone’s throw of chancellor Angela Merkel’s offices and the German parliament.
Mrs Merkel had previously confronted US president Barack Obama over allegations that the NSA bugged her mobile phone.
The ISC - chaired by former foreign secretary Sir Malcolm Rifkind - has already carried out a limited investigation into claims that GCHQ used the NSA's vast Prism programme, which gathers information from the internet companies, to circumvent UK laws.
Although committee cleared the agency of any wrongdoing in the 197 specific intelligence reports it looked at, it is now undertaking a wider inquiry into whether the laws governing surveillance are adequate for the internet age.
The committee’s questions will not be confined to communications surveillance, with the continuing terrorist threat to the UK also likely to be high on the agenda.
A statement on the ISC website makes clear however that they will not be looking at ongoing operations or cases which are currently the subject of legal proceedings.
“The committee will question the agency heads on the work of the agencies, their current priorities and the threats to the UK,” it said.
“Among other things it will cover the terrorist threat, regional instability and weapons proliferation, cyber security and espionage. However, since this is a public session, it will not cover details of intelligence capabilities or techniques, ongoing operations or sub judice matters.”
The hearing will be as much a test of the nine senior MPs and peers who make up the committee — which has always in the past taken evidence in private — as it will be for the agency heads.
Despite being handed additional powers and a wider remit as a result of the Justice and Security Act 2013, critics say the committee is still unable to provide effective oversight of the agencies.