Newly-released State papers show that campaigners against Irish participation in the European Economic Community (EEC) was monitored by Army intelligence in 1974.
A secret file on a leading opponent of EEC entry, Mr Anthony Coughlan, which has been declassified under the 30-year rule, shows the extent of monitoring by military intelligence.
Even minor details are recorded, such as a reference made to Mr Coughlan in a letter to the Sinn Féin weekly, An Phoblacht and the fact that he and his fellow-campaigner, Mr Micheál Ó Loinsigh, had "signed a letter to An Phoblacht".
A secret handwritten report, dated June 20th, 1974 indicates a high level of surveillance. The report notes that, "Tony Coughlan has been invited to a conference of the British-Irish Association in Oxford on weekend 5-7 July 1974. He has arranged to pass through London on 4 or 5 July. He is likely to stay with Desmond Greaves overnight 4-7-74."
A file was also kept on Mr Greaves, a British-based left-wing historian who died in 1988.
A report also tells how a body called the External Research Group had held its "third meeting" in Dublin in 1974. "The meeting discussed informally the theory and practice of developing a broad-based movement for democracy, unity and independence, as a credible alternative to the Fianna Fáil versus Coalition type of politics."
Among the participants understood to be present, the report continues, were Mr Coughlan, the scientist Dr Roy Johnston and anti-apartheid campaigner Mr Kader Asmal.