• D1097/1 Student Politics
• D1097/2 Volunteer Centre
• D1097/3 Political Campaigns and Constituencies
• D1097/4 By-elections
• D1097/5 Social Democratic Party Materials
• D1097/6 Co-operative Party Materials
• D1097/7 Personal Papers
• D1097/8 Publications

Michael Stuart Thomas, known as Mike Thomas, (born 24 May 1944) is a former British politician, identified with the Labour Party until 1981 and thereafter with the Social Democratic Party (SDP). He became well known for his role in both the establishment of the SDP and then in the SDP's subsequent demise. The SDP's leader, Roy Jenkins, referred to Thomas as the "pint-sized Pavarotti", on the basis of his stocky build and beard together with his aggressive manner. He studied at Liverpool University from 1962 to 1966, graduating with a BA degree. From 1965 to 1966 he served as President of the Liverpool University Guild of Students and from 1966 to 1968 he was a member of the National Executive of the National Union of Students. He initially made a career in political research, acting as head of the Co-operative Party's research department from 1966 to 1968 and as a research associate with the predecessor body of the Policy Studies Institute from 1968 to 1973.[1] He stood as the Labour Party candidate for the constituency of Hertfordshire (East) in the 1970 general election. On that occasion, Thomas lost to the Conservative Party candidate by a 14,000 vote margin.

Thomas continued in his quest to find a seat in Parliament and eventually succeeded at Newcastle-upon-Tyne East in September 1974. As a new Labour MP, Thomas served as parliamentary private secretary to minister Roy Hattersley from 1974 to 1976. He developed an interest in industrial and commercial matters, serving on the Parliamentary Select Committee on the Nationalized Industries from 1975 to 1979 and as Chairman of the Parliamentary Labour Party's Trade Group from 1979 to 1981. Once established as an MP, Thomas soon became associated with the Campaign for Labour Victory group of right wingers in the Labour Party led by MP and Environment Minister Bill Rodgers. In February 1981 Thomas was among a number of Labour MPs who defected to the new Social Democratic Party. During a final meeting with his constituency Labour Party, Thomas claimed that consultations with constituents convinced him that most of them supported his decision the leave the Labour Party. He declined to follow the advice of the constituency party that he should resign as an MP and contest a by-election.

Thomas remained in Parliament as an SDP MP where he acted as his new party's spokesman on health and social services. After losing his seat in Parliament in 1983, Thomas developed a portfolio of interests in journalism and management consulting. He was involved in various consultancies mainly concerned with media and public relations.