He was a Baptist minister and a chaplain with the Royal Air Force for returned prisoners of war.
He became a barrister, called to the bar by Lincoln's Inn, and a Queen's Counsel, and was bursar and a tutor at Manchester College, Oxford.
In 1969, Williams was appointed by the then-East Pakistan based Awami League, one of Bangladesh's main political factions since independence in 1971, to represent Pakistani and later-Bangladeshi politician Sheikh Mujibur Rahman in the Agartala Conspiracy Case.
The military junta of Gen. Ayub Khan did not allow Williams to represent Rahman, citing domestic security and interference in sovereign matters.
[1] In 1981, Williams, who had continued working as a barrister throughout his time in Parliament, was appointed a circuit Judge.