Patrick Daly, the agent, immediately reported back to MI5 and the police, who later helped him chose a quarry from where the explosives could be stolen and purchased a safe house - equipped with listening devices - where the INLA active service unit could stay, the jury was told.
In the dock at the Old Bailey in London are Martin McMonagle, 31, from Limerick, south-west Ireland - described by Mr Sweeney as a high ranking INLA officer - and Liam Heffernan, also 31, from Belfast arrested at a quarry in Somerset in February this year. They deny conspiring to cause explosions between 1 June last year and 8 February this year, plotting to steal explosives and possession of a .357 Sturm Ruger pistol.
Nigel Sweeney, for the prosecution, said: 'It was intended to use the stolen explosives to conduct a bombing campaign here on the mainland and in Northern Ireland. It was a campaign which had among its prospective targets MPs, the military, a ferry, a large oil terminal and a large gas terminal.'
Mr Daly, who lived in Bristol, was a member of the political wing of INLA, the Irish Republican Socialist Party; he had also been a police informer since the mid-Seventies, the court heard. In 1989, MI5 took over his control and he moved to Galway in the Irish Republic.
In July last year, Mr Sweeney said, Mr Daly was summoned to Belfast to meet Hugh Torney, described as INLA's chief of staff. Mr Torney asked him to identify a quarry from which explosives could be stolen, research the location of military bases and public houses used by military personnel and provide a safe house and garage to store explosives in the Bristol area, it was alleged.
The security service told Mr Daly that he was not to take part, but that he could conduct a reconnaissance of quarries, which he did along with his police controller. They took photographs of a suitable quarry at Westbury-sub-Mendip, which he eventually showed to Mr Torney, the court heard.
Mr Sweeney said that in December, Mr Daly was contacted by Mr McMonagle, whom he already knew, who said that he, together with a man called Anthony Gorman and Mr Heffernan would be going to England in February of this year to steal the explosives and that he should get a safe house for them.
Police acquired a three-bedroom house in a Bristol suburb and installed listening devices throughout; the sound was relayed to a police base in another house.
The jury were told they would hear evidence that the listening devices picked up the INLA team plotting bombings and of how Mr McMonagle described the killing of Conservative MP Airey Neave as 'a grand job', and how another one like it was needed.
Police decided that the INLA team would be arrested when they went to steal the explosives from the quarry store, Mr Sweeney said, but the operation was discovered at an early stage when Mr McMonagle accidentally stood on the back of a police surveillance officer. He and Mr Heffernan were arrested, but Mr Gorman escaped.
The trial continues today, when Mr Daly is expected to give evidence.Reuse content