[2] In the federal election of 1953, he ran as a candidate of the party in the predominantly middle-class riding of Winnipeg South Centre.

Penner left the Labour-Progressive Party in 1961, part of a mass exodus in the years following the Soviet invasion of Hungary and Nikita Khrushchev's secret speech on Joseph Stalin's crimes.

[9] On November 30, 1981, Premier Howard Pawley appointed Penner to be Government House Leader, chair of the Treasury Board, and attorney general.

He was also given ministerial responsibility for the Liquor Control Act on March 4, 1982, and stood down as Treasury Board Chair on July 28 of the same year.

Following a cabinet shuffle on September 21, 1987, Penner was named Minister of Education, while retaining responsibility for constitutional matters.

[9] The New Democratic Party experienced a significant decline in its popularity between 1986 and 1988, and Penner lost his seat to Liberal challenger Jim Carr in the 1988 provincial election.

[10] (The latter action resulted in a backlash in some parts of the province, leading to the rise of anti-bilingualism groups such as the Confederation of Regions Party.)

[2] Although he supported abortion rights, Penner was required to uphold a decision by the Manitoba courts which prevented Henry Morgentaler from opening a private clinic in the province.

Because of his background in communist politics, Penner was for many years forbidden from entering the United States of America under the McCarran-Walter Act.

In 1993, he openly questioned the attempts of Bob Rae's New Democratic Party government in Ontario to restrict tenure to professors deemed to hold socially unacceptable views.

[1] In 2010, it was revealed that Penner's name was on a secret list of Communist sympathizers kept during the Cold War; these persons were to be watched by the RCMP and could have been detained at internment camps in the event of a national security crisis.