While in office he served as deputy government whip as well as parliamentary secretary to the Ministers of Official Languages, Agriculture, and Veterans Affairs.

[3] His campaign generally focused on social conservative issues and increased personal liberties, including reducing the size and influence of government.

This included a proposed review of firearms laws,[4] term limits and Parliamentary votes for Supreme Court judges,[5] and opposition to a carbon tax.

[6] He also favours increased government powers for face-to-face immigration screening to combat "Radical Islamic Terrorism", though opposes a controversial "Canadian values" screening test proposed by another Conservative leadership candidate, Kellie Leitch, on the grounds that "terrorists won’t share their true values with [Canada's] immigration officials".

[7] In-line with many other Conservative Party leadership contenders, Lemieux has stated that he strongly supports Israel and its right to self-defence.

[11][12] His policies have been supported by the anti-abortion advocacy group Campaign Life Coalition as well as University of Toronto Professor Jordan Peterson.

[18] During his time as a Member of Parliament he voted in favour of Stephen Woodworth's M‑312, which sought to create a Parliamentary Committee that would study whether a child in the womb is a human being.

[14] He has also voiced strong opposition to M-103, a Parliamentary Motion of Liberal Member of Parliament Iqra Khalid, which condemns religious discrimination and makes particular note of Islamophobia in its preposition.