Stephen Maxwell

Stephen Maxwell, who has died aged 69, was a councillor, SNP activist and one-time leadership contender, leading theorist and outstanding contributor to Scotland's voluntary sector.

At the time of his death he had just completed his latest literary contribution, an analytical polemic Arguing for Independence. The proofs were at the publishers but, like his dream of independence, he would never see it come to fruition. The title was his lifelong rallying cry – once he had abandoned the Labour Party, appalled at Hugh Gaitskell's support for the nuclear deterrent.

His decision coincided with the rise of the independence movement in Scotland and sowed the seeds of a political career that would see him rise to prominence in the SNP and become a founding member of the Scottish Independence Convention, while lecturing and contributing professionally within the voluntary sector.

It was an extraordinary working life in which he inevitably put his principles before his own gain, political or otherwise – an attitude that cost him professionally on more than one occasion.

The son of a surgeon, who was killed in a car crash when Mr Maxwell was 14, he was born in Edinburgh and educated at Pocklington School in Yorkshire after the family moved south. Always interested in writing, he was a member of the school's literary society where he met poet Philip Larkin, sharing a train journey with the writer who had accepted an invitation to the society.

He won a scholarship to St John's College, Cambridge, where he graduated BA (Hons) in moral sciences in 1963. The following year he made his first attempt to become a journalist and had a brief and unsuccessful spell as a trainee on a newspaper in Sheffield. It came to an abrupt end when he was sacked for refusing to interview a grieving family whose daughter had died in dreadful circumstances.

He went on to complete his MSc at the London School of Economics in 1965, becoming the first to gain a distinction in his course, before tutoring at the LSE on strategic studies and lecturing in international politics at Sussex University.

Returning to Edinburgh in the early 1970s, he continued in academia on a Chatham House research fellowship in international affairs at Edinburgh University until 1973, later tutoring and lecturing on British government and politics, Scottish government and new political and social movements. He also taught social policy in Scotland at Edinburgh University, becoming an honorary fellow of politics and social policy there, and lectured at Glasgow Caledonian University's business management department.

Once back home he also embraced the cause of the Scottish Nationalists, where his rational thinking steered him towards political debate and theory. He became the SNP's national press officer from 1973-78, served as an SNP councillor for Wester Hailes on Lothian Regional Council from 1975-78 and held the vice-chairmanship of the party from 1978-82.

Unflinching in his support for independence, he was also national campaign director of the SNP devolution referendum campaign in 1979.

As a man who believed that nationalism and the left were synonymous, it was not surprising he became involved in the left-wing 79 Group, an internal SNP faction. Regarded as its principal intellectual driving force, he was the group's political theorist and stood in the SNP leadership election in 1980.

Although he never expected to win – and was defeated by Gordon Wilson – he saw it as another attempt to shift the terms and conditions of debate in the party to the left.

The 79 Group caused so much unrest in the party that the leading members, including Mr Maxwell and Alex Salmond, were expelled in 1981 but later re-admitted.

His link with the group also thwarted his second attempt to break into journalism in Scotland in the early 1980s when he was rebuffed, he believed, because of the 79 Group association.

He then worked in the voluntary sector, as national organiser of Scottish Education and Action for Development until 1985, followed by 25 years with the Scottish Council for Voluntary Organisations.

He was its social policy officer, head of policy and programmes, assistant director (development) and latterly associate director for 10 years until his retirement in 2009.

Over his many years there countless organisations benefited, directly or indirectly, from his work and insight. He led the SCVO's thinking on issues including social exclusion poverty, charity law reform and on aspects of developing a Scottish social economy.

In 2002 he was seconded to the Scottish Executive to develop policy for the promotion of the Scottish social economy. In the early days of devolution, he also worked alongside UK-wide voluntary organisations, helping them adapt to the new landscape.

He had attempted to become an SNP candidate at the first Scottish parliamentary elections but again his principles got in the way. He was ruled out after being unable to bring himself to pledge to consistently toe the party line.

A man of enormous personal credibility and clarity of purpose, he had a wide range of interests: he made at least one trip to the occupied territories of the West Bank, meeting whistleblower Mordechai Vanunu; struck up a friendship with novelist Margaret Atwood and was founding chair of the charitable company Carr-Gomm Scotland Ltd, providing support for 600 vulnerable people living in the community and increasing its income from under £2 million to £15m during his tenure.

He was also a founding member and office-bearer of the Scottish Independence Convention, an initiative to encourage cross-party and non-party co-operation, where he displayed an ability to bring serious analysis to every policy area without trying to avoid the difficult questions.

Yesterday Mr Salmond said: "During Stephen's long career he made an immense contribution to the national movement in Scotland, and was a key figure in the development of the modern SNP. I will remember his courtesy to all, his extraordinary intellect combined with gentle persuasiveness, and his lifelong service to others. His passing is a great loss to Scotland."

Stephen Maxwell is survived by his wife, Sally, and children Katie, Luke and Jamie, who aim to ensure his book on independence is published this summer.