MI5 was twice refused warrants to carry out covert surveillance by Theresa Villiers, the Northern Ireland secretary, it has been revealed.

The watchdog that oversees the running of MI5, the intelligence services commissioner (ISC), said the cabinet minister denied a request for two surveillance operations.

On Sunday, a human rights organisation in Belfast called for more transparency on the number of covert surveillance operations the secretary of state sanctions in Northern Ireland.

MI5’s regional headquarters is based at Holywood, Co Down, just outside Belfast, and up to 1,000 MI5 operatives are stationed there.

The ISC said the Northern Ireland Office took great care when considering requests from the counter-terrorism agency and that paperwork was in good order.



However, the commissioner, Sir Mark Waller, expressed concern about the breadth of language used to define the subjects on two urgent warrants, one that included intrusive surveillance – spying in relation to anything taking place on residential premises or in any private vehicle. He said: “The secretary of state for Northern Ireland shows a keen interest in the case for necessity and proportionality. She can and does refuse warrants.”

MI5 has the lead role in counter-terrorist operations across the UK, including in Northern Ireland. Its main task in the region is to spy on dissident Irish republicans in the New IRA, Continuity IRA and Óglaigh na hÉireann who oppose the peace process.

In one surveillance operation last year against a dissident republican faction in Newry, MI5 recorded more than 60 hours of conversations between alleged members of a terror group discussing potential police and army targets.

But the Committee on the Administration of Justice (CAJ), a human rights group, said the report “showed the inadequacy of the oversight of the secretary of state.”

Brian Gormally, the CAJ’s director, said: “The intelligence services commissioner says the secretary of state is doing her job – it would be strange indeed if he reported that she showed no ‘interest in the case for necessity and proportionality’.

“The fact that he thinks it is news that she occasionally refuses warrants demonstrates that the norm is that the secret MI5 normally gets its way. We need to know the number, type and justification of warrants for intrusive surveillance. More importantly, we need a genuinely independent and fearless form of oversight that can bring proper accountability to secret policing.”