Fletcher was the eldest of three children of Clarence George Eugene Fletcher (1875-1929), CBE,[1] of Oak Lodge, Bycullah Road, Enfield, London, a barrister and town clerk of Islington, formerly town clerk of Bethnal Green, and, as a recognized authority on the subject, a member of the Advisory Committee set up by the Home Office on registration of electors and conduct of elections,[2][3] and Nellie Molyneux, formerly of Tooting.

His paternal grandfather, George Fletcher, was a member of the Metropolitan Police Force attached to the Fulham Division.

[7][8] He studied at Radley College and the University of London and became a solicitor, specialising in international law.

In Harold Wilson's first government, he served from 1964 to 1966 as Minister without Portfolio, House of Commons spokesman for the Lord Chancellor's Department and then Deputy Speaker.

On 9 July 1970, he was created a life peer as Baron Fletcher, of Islington in Greater London.