Irish government officials, at the behest of Charles J Haughey, made strenuous efforts in October 1980 to prevent discussion in the Dail of the 'Donlon affair'.
Haughey had earlier planned to move Sean Donlon from his position as Irish ambassador in Washington to the equivalent post as representative at the United Nations in New York.
Word of this had caused alarm on both sides of the Atlantic because it raised fears of a more "republican" policy in Dublin.
The controversy is revived in State papers made public under the 30-year rule in the National Archives.
They show that the Taoiseach wanted a minute from a senior official in his department to be brought to the attention of the Ceann Comhairle.
It suggested that the Ceann Comhairle should rule out of order a question from Labour Deputy Michael O'Leary.
The central issue had already been settled, largely because of the intervention of the four top Irish-American leaders.
They were the 'Four Horsemen': Senator Edward Kennedy, Senator Daniel Patrick Moynihan, Congressman 'Tip' O'Neill and Governor Hugh Carey of New York.
The memorandum argued that the Dail question "concerns the assignment of a named public official to a particular post and asks if representations were received from certain individuals in this regard" (a clear reference to the Irish-American leaders).
It said that the Taoiseach did not consider that deputies had a legitimate interest in the appointment of named individuals to particular posts.
If such a question were allowed, it would open the way to discussion of the qualifications of named civil servants -- "a most undesirable development".
It has never been fully established why Mr Haughey planned to move Mr Donlon in the first place, but he certainly must have known what signal it would send out if it happened.
Mr Donlon personally, and the Four Horsemen, were heavily engaged in a "hearts and minds" battle for Irish-American opinion against Sinn Fein, the Irish National Caucus and Senator Mario Biaggi.
Had the ambassador been shifted from Washington, the Irish government would have lost the support and friendship of the American establishment and subsequent governments would have had difficulty in calling Washington to their aid when trying to devise a settlement in Northern Ireland.