Louis Plamondon

Louis Plamondon, a Progressive Conservative MP for Richelieu since 1984, left the Conservative caucus in June 1990 in the wake of the Meech Lake crisis and joined the nascent Bloc Québécois movement. Like many Quebec Conservative MPs, Plamondon had been elected as part of Mulroney's "beau risque" coalition — Quebec nationalists who gambled that working within federalism could secure Quebec's constitutional recognition. When Meech Lake failed, Plamondon concluded that Canadian federalism could not accommodate Quebec's aspirations and threw his lot in with Bouchard's separatist movement.

Plamondon became one of the Bloc Québécois's most enduring figures. He was re-elected in every election from 1993 through 2021 — the only BQ MP to survive the 2011 "orange wave" that reduced the party to 4 seats. By the time he retired, Plamondon had served continuously in the House of Commons for 37 years, becoming the dean of the House and one of the longest-serving MPs in Canadian history. His career spanned the entire arc of the BQ — from its founding to its near-destruction and partial recovery. He also participated in the 2018 Québec debout split from the BQ before returning.