Details of a threat to poison English water supplies have emerged in newly unsealed documents, which show British authorities took the plot seriously as it appeared technically feasible.
The British Embassy and the Papal Nunciature in Dublin received the threat in June 1999 on behalf of what was called the “Republican Revenge Group”.
It threatened to introduce weed killer into the water supply in England unless the British government announced its intention to withdraw from “occupied Ireland” by the following day.
The letters said an improvised chemical weapon would be attached to fire hydrants in England, forcing the chemical - a commonly available weedkiller called “New Pathclear” - into the water supply, potentially poisoning hundreds of thousands of people.
Although the threat might appear far-fetched, the British authorities took it seriously because the technical processes had been checked and were feasible, because the threatening letter was “cohesive and literate”, and because it had been sent to the right people in the UK, including the appropriate water authorities.
However, the British Embassy in Dublin thought the letter might be a dirty trick by loyalists designed to smear republicans.
The potential giveaway was references to “HMG” (Her Majesty’s Government) throughout the threat, a phrase unlikely to be used in earnest by a republican.
The authorities decided they had to take the threat seriously in the circumstances, even though it was thought the risk to life was low.
Most people who drank contaminated water would suffer nothing worse than a stomach upset, though it could threaten the lives of babies, and of people on dialysis.
The media in London - including RTÉ and the Irish newspapers - were called into a British government briefing and asked not to report the story, for fear of causing panic over what might well be a hoax.
The government promised that if a real threat was established, the public would be informed, and said that the media would be told whether or not anything happened when the deadline ran out.
Meanwhile in Dublin, gardaí were co-operating with British police and quickly identified a suspect.
They arrested an ex-soldier from Scotland living in Dublin. He was described by some observers as a “Walter-Mitty character” and he was never charged.
After his arrest, some details of the threat emerged, but not the precise technical details which caused the authorities to take it seriously. They are now available to view in papers released by the Irish National Archives.
