Last night in the House of Commons Mark spoke in support of the Covert Human Intelligence Sources (Criminal Conduct) Bill.

Covert Human Intelligence Sources (CHIS) - or agents - provide invaluable information to assist our security and intelligence agencies in their investigations and play a critical role in identifying and disrupting terrorist plots.

The CHIS Bill provides an explicit power for the Government to authorise agents to participate in conduct which would, in normal circumstances, constitute a criminal offence. This is not a new power. The Bill simply provides a clear legal basis for a long-established intelligence tactic which is vital for national security.

Participation in criminal conduct is an essential and inescapable feature of the activity of agents. It enables them to gain the trust of groups which pose a threat to the UK's national security, and to find information which other investigative measures might not detect.

Any authorisation for criminal conduct must be necessary, proportionate and compatible with the UK's obligations under the European Convention on Human Rights.