Tensions between the British and Irish Governments in 1978 have been revealed in State papers released this morning under the 30-year rule.

The tensions were generated by different approaches to the continuing upheaval in Northern Ireland.

The papers show that the British government of Jim Callaghan was worried about what it saw as a more Republican policy being pursued by then Taoiseach Jack Lynch.

In advance of the Fianna Fáil Ard Fheis in February 1978, Northern Secretary Roy Mason asked Mr Callaghan to phone Mr Lynch to warn him against making any 'inflammatory comments', a suggestion firmly rejected by the Prime Minister.

But Mr Callaghan's Foreign Secretary, David Owen, did ask Ireland's Foreign Minister Michael O'Kennedy to tone down his statements on the North, reporting back to London that Mr O'Kennedy was 'pretty unrepentant'.

Nationalists were equally suspicious of the British, especially Mr Mason.

John Hume of the SDLP told the Irish Government he had been 'amazed' when Mr Mason told him that Northern Ireland was entirely a British matter which had nothing to do with the Irish Government.

Showing his annoyance, Mr Hume said if this was true, he would be suggesting that Dublin might as well withdraw its security forces from the border and open up Portlaoise and Mountjoy prisons.

Watch Behind Closed Doors for more on these revelations this Friday at 8.30pm on RTÉ One Television and RTÉ.ie/Live