SIGNS of Unionist Party unease at the dramatic O'Neill Lemass "meeting of January 14th, 1965, were quick to emerge, according to confidential Cabinet files released in Belfast.
These documents also confirm that the meeting was undertaken by Capt O'Neill without prior consultation with his Cabinet and followed sustained pressure from the British government for improved relations between North and South.
The historic meeting dominated a conference between the Northern Ireland prime minister and the 10 Westminster unionist MPs a month later on February 19th, 1965.
Capt O'Neill recalled that in the Stormont debate on his first meeting with Mr Lemass (in which he had received the support of the great majority of MPs), he had laid emphasis on the wording of the Ireland Act of 1949 which had clearly established that no constitutional change could occur without the consent of the Northern Ireland parliament.
As far as trade was concerned, no dramatic developments were expected. The Minister of Commerce, Mr Brian Faulkner, was keen to explore possibilities in the field of tourism, but it was too dearly to predict any concrete result. In agriculture, there could now be direct contacts in relation to animal diseases and other matters of mutual interest.
Capt O'Neill told the MPs that whatever the practical benefits to be derived from such exchanges, and they might be limited, there was no doubt that the meetings had improved Northern Ireland's standing throughout the world.
The prime minister of the UK would have liked, in view of the importance of the Irish vote in Great Britain, to have claimed credit for the meeting but, in fact, it had been arranged on his (Capt, O'Neill's) own initiative.
As Prime Minister, Mr Macmillan had on three occasions asked him whether relations with the Republic could not be improved because of the embarrassment which the existing situation caused in America and elsewhere. Sir Alec Douglas Home had personally expressed his satisfaction.
To sum up, the constitution, as safeguarded by the Ireland Act, was perfectly secure. Without giving anything away, Northern Ireland's standing had been raised everywhere while Mr Lemass had announced he was meeting the Prime Minister of Northern Ireland" It had never been intended that the Border should be more than a political boundary the tariff wall had been raised by Eire as a result of the Trade War.
Capt L.P.S. Orr (MP for South Down) said he fully accepted that the invitation to Mr Lemass was an act of statesmanship. Mr R. Chichester Clark (MP for Co Derry) felt it would be undesirable to have joint North South trade promotions in Great Britain. The prime minister agreed, although he observed that linen firms were accustomed to "selling under the Tricolour" in the US.
However, the MP for South Antrim, Sir Knox Cunningham, referred to the prime minister's earlier statement that "non recognition" was an obstacle to any meeting between the two prime ministers and asked how this policy was affected by the meeting which had taken place.
Capt O'Neill said there could be no disagreement as to what de facto meant. For his own part, he considered it an immense advance that the prime minister of the Republic should meet him at Stormont as prime minister of Northern Ireland.
No Irish prime minister could alter the Eire constitution and hope to remain in office. The most that could realistically be expected was the kind of de facto recognition which had now emerged. The decision to invite Mr Lemass had been his own, as had been the decision of Lord Craigavon to meet Mr de Valera in Dublin (in 1921).
The main plank of the unionist platform would remain the maintenance of the constitutional position. But this did not mean that it was wrong to discuss matters of common interest with their nearest neighbours on the same island. They continued to disagree with them, but could do so in a civilised way.
But Mr James Kilfedder (MP for West Belfast) expressed deep concern about the meeting. Many in the Republic supported Mr Lemass's moves since they saw in it a cunning stratagem to weaken Northern Ireland's position by diplomatic means.
The prime minister replied that he had no plans for any further meetings at an early date. He recognised that some members were faced with problems in their constituencies, but Stormont MPs faced similar problems and the great majority had the courage to back him. He was convinced that the North's standing in Britain and the world had been raised.