[1] Following his education, he was called to the Bar (Gray's Inn) in 1973,[3] and Harrington practiced from chambers in Cardiff for twenty years.
After a "successful" first year in silk, he was invited to join the Chambers of Lord Williams of Mostyn QC at Farrar's Building.
He is a keen sportsman, serving as a member of the Ebbw Vale RFC and Glamorgan County Cricket Club.
[2] Following the incident, Ebbw Vale Rugby Club President Mark Powell QC issued a statement of condolence.
He praised Harrington for his "considerable role alongside the Russell family during the glory years of professional rugby".