The RUC was dissatisfied at the level of co-operation from the Garda Síochána during Charles Haughey's minority administration, previously confidential Northern Ireland records from 1987 confirm.

The charge surfaces in a memo on issues raised by the minister for foreign affairs in the Fianna Fáil government, Brian Lenihan, with the secretary of state for Northern Ireland, Tom King, dated June 24th, 1987.

SG Hewitt of the Northern Ireland Office reported that the heads of the two police forces had met and were working on an “in-depth study of the Provisional IRA”. Their aim was to produce an agreed intelligence assessment which would inform joint action to deal with the IRA threat.

Mr Hewitt added: “The meeting itself was far from satisfactory. The [RUC]chief constable [Sir John Hermon] reported that little or no pre-emptive intelligence had been provided by the Garda Síochána. During discussions the [Garda] Commissioner showed little evidence that they really understood what was being asked of the Garda . . . or that he was prepared to make the structural changes considered necessary by the RUC for effective co-operation in the intelligence field.”

As a result it was arranged for commissioner Ryan of the Garda Síochána to be briefed by assistant chief constable Forbes of the RUC on intelligence matters. Ryan had sent a report to the appropriate Irish ministers and the taoiseach, Mr Haughey, the official noted.

In a letter to the secretary of state, Mr Lenihan had pressed Mr King for figures on RUC accompaniment of military patrols in the early introduction of the long-standing nationalist demand for a “code of conduct” for the RUC.

Both issues were strongly pressed by the Irish government at intergovernmental conferences since 1985. The British said the chief constable was committed to the “code” and this, according to the minute, “helped to defuse Irish concerns in the run-up to the election in the South”.