- guardian.co.uk, Wednesday May 31 2000 01.33 BST
It has refused to deny claims, first made last year, that it tapped the phones from a tower at Capenhurst in Cheshire.
The tower - described by the Ministry of Defence as an "electronic test facility" - intercepted phone calls carried by radio microwave between British Telecom relay stations at Gwaenysgor, Clywd, and Pale Heights, near Chester.
The stations carried Ireland's telecommunications links through Britain.
The government has never denied claims about the purpose of the Capenhurst tower which were first made by Channel 4 News in July last year.
Lawyers representing the Irish Council for Civil Liberties, Liberty, its British counterpart, and British Irish Rights Watch, claim the interceptions breached article 8 of the European human rights convention guaranteeing the right to privacy.
The Capenhurst tower, they said, had the capacity to intercept 10,000 simultaneous phone channels from Dublin to London and elsewhere. Tapped conversations included legally privileged material such as discussions between human rights groups and individuals who sought their assistance, they said.
They pointed to a section of the 1985 Interception of Communications Act which allows the security and intelligence agencies to seek warrants enabling them to tap conversations without referring to a specific target or address.
The act allows the home secretary to issue a warrant covering any information the agencies say they need to carry out their functions - so-called "certified" material - from "external communications".
However, they can only gather this material by intercepting other conversations and information passing through the communications link.
"The procedure ... by its nature requires all material, regardless of whether it falls within the scope of the purposes defined in the warrants or not, to be intercepted," Richard Clayton, counsel for the human rights groups, said in their submission to the European court.
He added: "The material is then examined after the event in order to discover whether it falls within the scope of the warrant." He said the 1985 act effectively allows interception for "any purpose".
The Capenhurst tower is redundant and up for sale and Ireland has a new fibre optic telecommunications system. Early this year, David Andrews, the former Irish foreign minister, said he accepted assurances from Robin Cook that Britain was not involved in indiscriminate or blanket tapping of Irish communications.
Minutes of an Irish security committee, released under the country's freedom of information act, concluded there was "no firm evidence available to the Irish authorities that commercial telecommunications traffic originating in or destined for this country has been intercepted in a systematic or extra-legal way".
However, members of the committee argued that interception technology in possession of many countries, including Britain, suggests that illegal bugging is going on.
The human rights groupsbringing the test case argue that indiscriminate bugging is being allowed by existing English law in contravention of the human rights convention.
John Wadham, director of Liberty, said yesterday that the loophole in the 1985 act will remain in the new regulation of investigatory powers bill which gives the security and intelligence agencies sweeping new bugging powers.
