The Unionist government warned Whitehall of massive violence from the Protestant community if the Labour government attempted to impose direct rule in August 1969, according to the Cabinet releases.
The papers reveal that on Sunday, August 3rd, 1969, the secretary to the Northern Ireland Cabinet, Mr H. Black, contacted the Home Office in London.
Mr Black informed officials that the Northern government "might be approaching the point when, with continued disorder in Belfast, the police might no longer be able to contain the situation and we would have to seek the help of the army".
The Stormont official asked that the British government should be alerted to this possibility so that any "prior approvals" could be obtained.
Later that evening, however, Mr Black was informed by the Home Office that the British government was not prepared to give any prior approval in principle, and that the decision was based on the GOC's assessment that the police could deal with the present situation alone.
The Cabinet secretary informed the Stormont minister: "I was told that in view of the serious constitutional consequences of the use of troops, it would be advisable for Northern Ireland to endure a quite considerable degree of disorder before involving military assistance."
When Mr Black asked the Home Office the precise nature of "the constitutional consequences", he was informed that the British Home Secretary, Mr James Callaghan, believed that "if he decided to put troops on the streets, he might be committing the UK government to take over the government of Northern Ireland". In a searing memo, Mr Black informed Stormont ministers: "To all this I felt it was necessary to express my astonishment that such penal consequences could be contemplated; that it had never occurred to us that the veiled hints at the Downing Street meetings about `review of the constitutional relationships' had ever meant more than the possible removal of responsibility for law and order - an extreme enough step in all conscience - and that NI Ministers were bound to react vigorously against this attitude."
In a warning to Whitehall, Mr Black made the unionist cabinet's feelings clear to Sir Philip Allen of the Home Office:
"The UK authorities should consider the situation that might arise if, in fact, they did decide to exercise direct rule from Whitehall. There would, first of all, be a frightening reaction from the Protestant community which could make anything that has happened up to now seem like child's play; a provisional government might be set up with extreme elements at its head and it was highly probable that wholesale sectarian strife would break out, not only in the streets, but in the factories.
"The action proposed by HMG was surely only proper in the case of a recalcitrant and intractable government which was resisting desirable reforms. The present administration in Northern Ireland, far from being reactionary, had embarked upon every reform suggested to them by London and were completely committed to the implementation of reform."
He concluded: "The UK authorities should be in no doubt whatever that in the NI view, the suspension of a democratically-elected government would lead to a major constitutional convulsion and the repercussions in terms of violence and civil strife would be very grave indeed."
In further discussions, the Home Office agreed that the possibility of a takeover by Westminster of the functions of the Northern Ireland government was a rather remote possibility, but one that could not be excluded from consideration.
Two days later, on August 6th, 1969, the Stormont prime minister, Maj Chichester-Clark discussed the situation directly with the Home Secretary on the telephone. Mr Callaghan stated that the British government had no intention or desire to resume responsibility for Northern Ireland affairs.
The two situations in which this might arise were (a) in the event that progress on the reforms discussed at previous Downing Street meetings was not satisfactory; and (b) the continued use of troops to control riot situations. However, the Home Secretary stated that the Stormont government was to be congratulated on its progress in implementing reforms so far.
In the case of the continuing use of troops in the North, Mr Callaghan expressed his view "that it was a case of taking over all Northern Ireland's affairs or none". He would, however, instruct his officials to examine the possibility of taking over law and order only.
In an interesting aside, Mr Callaghan "particularly emphasised the need to recruit Roman Catholic police".
These developments were discussed at a Cabinet meeting at Stormont on August 11th, 1969. Ministers agreed that as the overriding consideration was to avoid the use of troops, top priority should be given to the strengthening of the RUC and the deployment of the Ulster Special Constabulary.
Ministers were insistent that the Home Secretary should be informed of the government's objection to the suspension of the Northern Ireland government, as envisaged by the Home Secretary in the event of troops being deployed in a peace-keeping role.