THE Very Rev Dr William B Johnston, Moderator of the Church of Scotland General Assembly in 1980, was one of the major figures in the ecumenical affairs of the churches in the British Isles.

During the 1980s, he took a leading role in both the British Council of Churches (BCC) and the Scottish Churches Council, serving as BCC executive committee chairman.

During his long ministry at Colinton, Edinburgh, from 1964-1991, Bill Johnston was also one of the relatively small number of parish ministers who could really be called leaders of the Church of Scotland.

He was successively convener of the Church and Nation Committee and the InterChurch Relations Committee, and later served as chairman of the judicial commission of the General Assembly. He had also been convener of the Kirk's committee on adult education and a special committee on the "role of men and women", as well as chairman of the editorial advisory committee, offering advice to editors of the Kirk magazine, Life and Work, but never forcing it upon them. In 1975, he was a delegate to the Assembly of the World Council of Churches in Nairobi.

Born in 1921, William Bryce Johnston belonged emphatically to Edinburgh, where his father was a civil servant.

He was educated at George Watson's College and Edinburgh University, taking honours in classics before divinity at New College.

In 1945 he was ordained as an Army chaplain, serving first with the 5th King's Own Scottish Borderers and then as a War Office PoW staff chaplain, where he experienced what he called an "ecumenical indoctrination" through his work in screening and helping German Protestant clergymen who had found themselves in captivity after serving in the German army without recognition as chaplains.

He returned to Scotland in 1949 as minister of St Andrew's, Bo'ness, and moved to St George's Greenock in 1955 for a nine-year ministry which gave him a real understanding of the west of Scotland.

But his return home to Edinburgh (after a choice in Colinton which was described - perhaps apocryphally - as "between a nice boy from Heriot's and one from Watson's") enabled him to combine an astonishing intensity of committee work with a diligence in high-quality preaching and pastoral work which imposed severe demands on him. He was not the kind of committee minister who neglected congregational or parish visiting.

He may have taken too much on himself, although he was already contemplating retirement when he suffered a stroke in 1990. He recovered well enough to resume writing and to chair the hearing of awkward cases in the judicial commission and at the General Assembly itself.

His moderatorial year was a natural recognition of his talents, though his aptitude for elder statesmanship denied him much credit for being one of the few Moderators appointed before the age of 60. His term was notable for a very successful visit to Jerusalem to mark the jubilee of the Scots church there, when he did not disappoint an international and ecumenical gathering who had come to see if Scots preaching was all it was cracked up to be, and by a brush with supporters of the Thatcher government early in 1981.

In a sermon in St John's, Perth, referring to youth unemployment, he spoke of a sense of rejection and frustration and asked if any economic theory could justify this "derogation of human life". It also appeared to call such policies immoral and blasphemous, though the sermon referred to the evil in society and, in response to the criticisms, Dr Johnston later said he was referring to responsibilities "of our total society".

He had been widely assumed to be replying to an address on wealth creation given in a London church by Mrs Thatcher, but his text had been written and given to the Kirk's press office before the Thatcher speech. In retrospect, the Perth sermon might be seen as the opening of a breach (which later greatly widened) between the Kirk's establishment and the Conservative government.

Ironically, the Moderator who delivered it took a far more moderate view of politics than many of his successors in the chair and in the Church and Nation convenership.

Bill Johnston had sharpness of mind and usually a crispness of phrase and judgment which could on occasion tend towards a slight acerbity of manner. He did not suffer folly gladly, though he sometimes suffered them in silence. He was restrained in expressing his fears that the reorganisation of ecumenical relations in Scotland (after the readiness of the Roman Catholics to join in) was being done in a way which could endanger Scottish influence in the wider ecumenical affairs of the British Isles.

Nor did he comment in public on trends in the handling of Church and Nation affairs in the Kirk, although he thought the Church risked loss of its real moral authority by becoming a pressure group, especially when allied to campaigns close to party politics.

In theological matters, he feared an ultra-conservative reaction which could even become a fundamentalist takeover and, although strongly attached to Presbyterian and Reformed ways, he had much in common with such broadly liberal Anglican churchmen as DrJohn Habgood, the Archbishop of York.

Dr Johnston's distinctions ranged from appointment as a chaplain to the Queen in Scotland (1981) to the translation of works by Calvin and Barth. He served on the Broadcasting Council for Scotland (and was himself an effective broadcaster) and was a visiting lecturer in social ethics at Heriot-Watt University. He was awarded doctorates from Aberdeen (D.D. ) and Heriot-Watt (D.Litt). He was president of Edinburgh Rotary Club from 1975-1976 .

He married, in 1947, Ruth Cowley, a daughter of the manse, whom he met while he was an Army chaplain and she was serving as a Wren with a naval unit in post-war Germany. They had a son and two daughters.