Mulcair announced on December 18, 2017, that he would be resigning his seat of Outremont, after the House of Commons rises for its summer break, to accept an appointment at an undisclosed university,[1] later revealed to be the Université de Montréal.

[2] Mulcair's resignation came after the rise of internal leadership and ideological differences within the NDP, following the release of the Leap Manifesto.

Carpenter ran unsuccessfully in 2017 to unseat Lionel Perez as the Montreal City Councillor for the borough of Côte-des-Neiges–Notre-Dame-de-Grâce in Darlington district.

Principal of Concordia University's Simone de Beauvoir Institute Kimberley Manning had declared her intention to seek the Liberal nomination.

[7] Former Notre-Dame-de-Grâce MNA and Côte-des-Neiges–Notre-Dame-de-Grâce borough Mayor Russell Copeman[8] and federal Liberal riding president David Marshall[9] were rumoured candidates for the nomination.