At the
1950 and
1951 general elections, Thomson stood unsuccessfully in
Glasgow Hillhead. In 1952, he was elected Member of Parliament in
a by-election for
Dundee East, where he served until his resignation in 1972. He served in the
Wilson government as
Minister of State,
Foreign Office, from October 1964 to April 1966, then as
Chancellor of the Duchy of Lancaster from 1966 to 1967, and again from 1969 to 1970,
Secretary of State for Commonwealth Affairs from 1967 to 1968, and
Minister without Portfolio from 1968 to 1969. During his time as Commonwealth Secretary he had responsibility for trying to reach a settlement of the
Southern Rhodesia (now Zimbabwe) question and for implementing sanctions against the regime there. He was one of the first British Commissioners of the
European Community (EC) from 1973 to 1977, with responsibility for regional policy. As chairman of the
Independent Broadcasting Authority (IBA) from 1981 to 1988 he oversaw the introduction of Channel 4 and TV-am. He was Chair of the
Advertising Standards Authority from 1977 to 1980; Chair of the IBA 1981–88; a
European Commissioner, with responsibility for
Regional Policy 1973–76; First
Crown Estate Commissioner from 1977 to 1980; and a Member of the
Committee on Standards in Public Life from 1994 until 1997. He was Deputy Chair of the
Woolwich Building Society from 1988 to 1991. He had been a Lords' Member of the Parliamentary Broadcasting Unit since 1993. He was a Fellow of the
Royal Society of Edinburgh and the
Royal Television Society, and a patron of
Sustrans. In 1985 he was invited to deliver the MacMillan Memorial Lecture to the Institution of Engineers and Shipbuilders in Scotland; he chose "Does Public Broadcasting Have a Future? The Challenge of the New Technologies". After moving with his wife, Grace, to
Charing, Kent, Thomson held the position of Party President, for Ashford Liberal Democrats, from 1999 to 2006. ==Death==