Sabbatarians who refused to work Sundays were to be excluded from bunker control teams for responding to a nuclear attack on Northern Ireland, official archives reveal.
Members of the key units were also selected on grounds of physical fitness and age, according to NIO documents from 1983.
Although the files are older than others being released from 1986, they are being declassified now as the files were not closed until 1986.
The draft criteria were to be used in the selection of new members for four area control teams situated in the north, south, east and west.
The paper from the Home Defence Planning Committee said that up to 75 people were intended to form a team within two days, with appropriate accommodation and communications.
It said that the need for the setting of criteria has been made apparent by the quality and enthusiasm of existing team members: “It is apparent that a percentage of the existing team members lack enthusiasm and their efficiency obviously suffers.”
Other proposed criteria included family commitments, with those who had large families judged to be “undesirable” for the role “as they may be more inclined to put family responsibilities first, making arrangements for their well-being”.
The draft guidance also covered physical disabilities: “Given the conditions within the bunker with all its constraints on both space and facilities and indeed the very nature of the work expected of team members, persons with any physical disability except those of a minor nature would be at a disadvantage.”
It said an upper age limit of around 50 should be set for health reasons but acknowledged wide-ranging knowledge of an organisation was likely only after years of service. Those with specialised dietary requirements and those who required medical drugs would be undesirable.
The final criteria covered membership of outside groups.
“We should avoid nominees who hold sincere views of the nature of Lords’ Day observance, Exclusive Brethren etc.”