Writer and political activist; Born July 7, 1942; Died September 5, 2007. DERRICK O'Clancy White, who has died in Spain from cancer, was a Dubliner who for the past three decades had made Scotland his home. He became well known as a political activist and parliamentary candidate, first for the SNP and then for the Scottish Socialist Party.

He was the youngest of three sons of Captain Jack White (1879-1946), founder of the Irish Citizen Army which took part in the Easter Rising of 1916, and grandson of Field Marshal Sir George White VC, Colonel of the Gordon Highlanders, who was known for holding Ladysmith during its siege in the Boer War.

Jack White died when White was not yet four and after attending Blackrock College, Co Dublin, White joined the Royal Navy as a boy recruit at the former HMS Ganges in Suffolk. After service in the navy as a communications specialist and marksman, he returned for a short time to Dublin around 1970, driving an ambulance for a specialist cardiac service and working in a health club.

He then came to Scotland, where he launched his own health clubs in Queen Street, Glasgow, and Stafford Street, Edinburgh, which operated successfully for some 10 years.

When these businesses dissolved he moved to England for several years, working for the multinational company, Canon, in training and recruitment before returning to Scotland where he set up his own training consultancy.

During the 1990s he became active in the Scottish National Party, standing as its candidate for the Westminster parliamentary seat of Edinburgh East and Musselburgh in 1997, where he took 19% of the vote.

Becoming disillusioned with the SNP, he joined the Scottish Socialist Party, standing unsuccessfully for the Scottish Parliament seat of Edinburgh East and Musselburgh in 1999 and the Westminster seat of East Lothian in 2001. He remained a much respected member of the SSP right to the end, staying loyal to the party after the recent split.

White inherited his father's and mother's literary talents and wrote a series of books on training, sales, personality profiling and psychometric testing, and numerous articles on politics for the Scottish Left Review.

He was a frequent contributor to The Herald's letters page, specialising in attacks on what he saw as political hypocrisy wherever he found it. Honed by experience as a particularly entertaining part-time bus tour guide in Edinburgh, his last published book, Scotland, Frequently Asked Questions: What Every Visitor Needs to Know (2004) is a richly humorous exploration of the sore points of Scottish history and psychology.

Before his death he had completed a further book, giving a tongue-in-cheek view of what's wrong with Britain and justifying his move to Spain.

White fought his battle against cancer with remarkable bravery. He is survived by Andrew, his son by his first wife, Jennifer, and by his second wife, Bernice, whom he married in 1996.