After placing second to
Liberal candidate
David Croll in the Toronto riding of
Spadina in the
1945 federal election, he won election to the
House of Commons of Canada in a 1950 by-election in the nearby riding of
Broadview. He was also President of the Progressive Conservative Party from 1953 to 1956. He considered running for the party leadership when
George A. Drew was forced to step down in 1956, but instead supported the campaign of the eventual winner,
John Diefenbaker. When the PCs under Diefenbaker won government in
1957, Hees was named
Minister of Transport, and oversaw the opening of the
Saint Lawrence Seaway and the new
Halifax International Airport. In 1960, he was appointed
Minister of Trade and Commerce. During this period, Hees was regarded as the second most powerful man in the Tory party. However, in 1963, he fell out with Diefenbaker, and became embroiled in the
Munsinger Affair and elected to sit out the
1963 election. In that election, the Liberals replaced the Tories'
minority government with one of their own, causing Diefenbaker's succession with
Lester B. Pearson as
prime minister. Hees considered leaving the Conservatives for the Liberals, but did not do so. He became president of the
Montreal Stock Exchange. He returned to Parliament in the
1965 election as a PC, defeating Liberal MP
Pauline Jewett in the rural riding of
Northumberland, and remained in the front rows of the opposition ranks for almost two decades. He ran for the leadership of the PC Party at its
1967 leadership convention, and placed fourth in a field of eleven on the first ballot. He remained for two further ballots before withdrawing, and supporting the eventual winner,
Nova Scotia Premier Robert Stanfield. He was noted for being involved in a
1972 election campaign incident. On 22 September 1972, Hees forcefully ejected campaign worker Douglas MacDonald from his motel room in
Trenton, Nova Scotia. He struck MacDonald's head against the door, shattering some glass that lacerated him in several places. During the trial, Hees tried to plead self-defence. His plea failed and on 22 February 1974, the
Nova Scotia Supreme Court ordered him to pay $6,175 to MacDonald. He was not named to Cabinet during the
Joe Clark government in 1979–80, and was quoted saying, as Clark stepped down in the 1983 leadership race, "We've got him! We've got the S.O.B." In 1981, Hees was the Chairman of the Canada-US Permanent Joint Board on Defence. In this role, he was the first Canadian to bring to the attention of then-Prime Minister
Pierre Trudeau the US request to test nuclear-capable cruise missiles over Canadian territory. When
Brian Mulroney led the party to a majority government in
1984, Hees was named
Minister of Veterans Affairs. Hees retired from politics at the
1988 Canadian federal election. In 1989 he was made an Officer of the
Order of Canada. There is a veterans wing at Toronto's
Sunnybrook Health Sciences Centre bearing his name, and near the relocated
Crescent School he attended as a child. ==Election results (partial)==