He entered the cabinet within a year as Attorney General of Ontario under then PremierJohn Robarts. He served in that senior cabinet portfolio for seven years, and is credited with shepherding many important pieces of legislation, including the Legal Aid Act of 1966 and the Law Enforcement Compensation Act of 1967.
In 1967, Wishart fired Morton Shulman from his position as Chief Coroner of Metropolitan Toronto as a result of Shulman's criticisms of the government's failure to follow various recommendations made in coroner's inquiries. The dismissal propelled Shulman, until then a long-time Tory, into politics as a candidate and then MPP for the New Democratic Party.
In early 1971, Wishart became Minister of Financial and Consumer Affairs under Robarts's successor, Bill Davis,[3] and served until retiring from politics at the 1971 provincial election.
Wishart was very active on the issue of franchises while he was Minister of Finance and Minister of Consumer and Commercial Affairs. He initiated the Grange Commission, an inquiry held into the financial abuse of franchisees by franchisors. The Arthur Wishart (Franchise Disclosure) Act, passed in 2000 was named in his honour.
After leaving politics, he served the province as chairman of the Criminal Injuries Compensation Board and later of the Commission on Election Contributions and Expenses. He returned to Queen's Park in 1973 as a liaison between Premier Davis and the Progressive Conservative caucus.
^Manthorpe, Jonathan; Slinger, John (March 2, 1971). "Changes in policies promised: Davis priorities to include environment and jobless". The Globe and Mail. p. 1.
