He served in the Legislative Assembly of Ontario from 1981 to 1987, and was a cabinet minister in the governments of Bill Davis and Frank Miller.
[2] Andrewes supported Frank Miller to succeed Davis in the Progressive Conservative Party's January 1985 leadership convention, and was appointed Minister of Agriculture and Food when Miller became Premier of Ontario on February 8, 1985.
[3] Andrewes was re-elected in the 1985 election with an increased plurality, although the Progressive Conservatives were reduced to a fragile minority government in the legislature.
[4] He was promoted to Minister of Health on May 17, 1985, but accomplished little in the department before the Conservatives were defeated in the legislature a month later.
[6] After leaving politics, he served for many years as chair of the board of directors for Agricorp, an Ontario crown corporation.