Peter Barry, the foreign affairs minister, sought approval in June 1986 to sign a proposed agreement with the US government to set up a pilot facility that would allow US-bound air passengers undertake all immigration and public health inspections at Shannon prior to departure.
Files show Mr Barry accepted the establishment of a pre-inspection facility, which would allow the application of US immigration and public health laws operate on Irish soil, was “a matter of concern in principle and in practice”.
He claimed its provisions which touched on Irish sovereignty were as limited and tightly drafted as possible, while ensuring US agreement would also be secured to operate the pre-inspection facility.
The initiative to set up the pilot programme, to come into effect on July 1, 1986, was originally proposed by the communications minister, Jim Mitchell.
Mr Barry admitted that immunities conferred under the draft agreement on US officials at Shannon represented a novel departure from legal precedent as it sought to confer a status equivalent to diplomatic immunity on them.
Mr Barry also informed the cabinet the actual cost to the State arising out of signing the agreement could not be quantified. The US agreed it would cover the cost of any diagnostic tests carried out on passengers suspected of having an infectious disease.
The US operated on the principle that pre-inspection facilities must be self-financing but it agreed to fund the cost of posting staff to Shannon during the pilot phase.
It was agreed such staff would not be armed.
Records also reveal a proposal to include customs pre-clearance at Shannon was resisted by Aer Lingus. The airline was concerned about delays which would arise for flights to the US because of the need to offload baggage at Shannon to process it through customs.