The Munsinger Affair was Canada's first political sex scandal. It focused on Gerda Munsinger an East German prostitute and Soviet spy living in Ottawa who had slept with a number of cabinet ministers in John Diefenbaker's government. Most noted amongst these was the Associate Minister of National Defence Pierre Sévigny who had seen her since 1958 and had even signed Munsinger's application for Canadian citizenship. The RCMP discovered her background, however, and informed Justice Minister David Fulton of here activities. She was deported to East Germany in 1961. The matter was dealt with behind closed doors and Sevigny resigned in 1963.

Traditionally in Canada the personal lives of politicans is not discussed in parliament or in the media, but in 1966 the Liberal government was under attack for an unrelated security breech. On March 4 and angry Justice Minister Lucien Cardin rebutted the Tories by bringing up the Munsinger affair in the House of Commons. The story dominated the media for weeks and was followed with rapt attention across the country. It became a massive distraction and all but shut down all other parliamentary activity for some weeks.

Munsinger was found living in Munich, despite the government insisting she had died of leukemia and freely admitted her numerous affairs with government officials to the Canadian media. A Royal Commission was eventually held that criticized the Diefenbaker government's handling of the case but found no criminal wrong doing or security breach.