It is important that there is proper oversight of the work and actions of our intelligence and security services, particularly in light of the recent revelations. More needs to be done to make this a reality, but we must also of course balance the need for transparency with the operational effectiveness of the security services.

Lib Dems in government passed legislation in 2012 to transform the powers of the Intelligence and Security Committee (ISC), a cross-party Commons committee that has oversight of the intelligence services, including GCHQ. The Bill gave the ISC new powers to call for evidence from the intelligence services, hold them to account, and to select the membership of the committee themselves, rather than being appointed by the Prime Minister. The ISC will have a role in overseeing the wider government intelligence community and have retrospective oversight over operational activities on matters of significant national interest.

The recent intelligence and security committee hearing at which the Heads of MI5, MI6 and GCHQ gave evidence confirming the principle that open debate over security is possible and necessary, although clearly this is only a start.

You may be interested to know that in my role as Minister of State at the Home Office I am, at the request of the Deputy Prime Minister, actively considering the wider matters relating to the security services and in particular the balance between liberty and security. I am sympathetic to the idea of a review of how existing security and surveillance measures are working in practice, and a review of the Regulation of Investigatory Powers Act (RIPA), which regulates the powers public bodies have to carry out surveillance and investigation, including the interception of communications would also be helpful.