Guillaume is known for his determination and creative approach to developing solutions for clients’ issues.
Guillaume has represented clients at all levels of court, including the Supreme Court of Canada, and before tribunals. He acts on complex matters that often involve administrative, constitutional or regulatory ramifications. He is also involved in class actions dealing with human rights and Crown liability.
Guillaume is president of the Administrative Law Section of the Canadian Bar Association Québec Branch.
Montréal Defence Lawyers Association
Represented the Montréal Defence Lawyers Association (AADM) before the Supreme Court of Canada in Attorney General of Quebec, et al. v. 9147-0732 Québec Inc., a case where the Supreme Court of Canada will determine for the first time if the constitutional protection against "cruel and unusual treatment or punishment" should apply to corporations as well as to other legal persons.
Acting for proposed class representative René Allard in a class action proceeding regarding constitutional damages against the government of Québec on behalf of retired members of Québec's public and parapublic sectors' management personnel, as well as their spouses, whose retirement pension indexing was unilaterally suspended and retrospectively modified by a statute adopted by the Québec National Assembly.
Formula E Operations Ltd.
Acting for Formula E Operations Ltd. (FEO) in connection with its claims arising from the City of Montréal's decision to cancel the Montréal ePrix. This includes asserting FEO's claims against the City of Montréal and in the bankruptcy proceedings of Montréal C'est Électrique, a non-profit corporation set up by the City for the purposes of acting as promoter of the Montréal ePrix.
Association québécoise des pharmaciens propriétaires
Acting for the Association québécoise des pharmaciens propriétaires in a motion for declaratory judgment against the Attorney General of Québec and the Régie de l'assurance maladie du Québec concerning the interpretation of a recent statute adopted by the Québec legislature regarding certain obligations imposed upon all pharmacists in Québec.
Acted for the plaintiffs in a class action involving all Québec parents who were required to pay fees for the purchase of school books or other didactic material even though these fees should have been assumed by the school boards.
Can the State Be Held Liable for Neighbourhood Disturbances?
June 17, 2020 - In Maltais c Procureure générale du Québec, 2020 QCCA 715, the Québec Court of Appeal rendered an important decision regarding Crown liability. Its decision clarifies whether the regime of no-fault liability for neighbourhood disturbances applies to the government. It also contains...
New Beacons of Administrative Law: Top Court Reviews the Approach to Judicial Review of Administrative Decisions
Jan. 14, 2020 - The Supreme Court of Canada (SCC) recently rendered its much-awaited decisions in Canada (Minister of Citizenship and Immigration) v Vavilov and companion appeals. Upon granting leave to appeal, the SCC had announced that these appeals would “provide an opportunity to consider the nature...
Québec Superior Court Enforces Right to Collective Bargaining of State Employees
Oct. 08, 2019 - The Québec Superior Court (QSC) recently struck down as unconstitutional back-to-work legislation (Bill 127 1 ) aimed at the Québec government’s advocates and notaries. The decision, released on September 18, 2019, builds on the recent case law of the Supreme Court of Canada which declared that...
Québec Court of Appeal Says Current Civil Jurisdiction of the Court of Québec Is Unconstitutional
Sept. 17, 2019 - A seven-member panel of the Québec Court of Appeal (QCA) recently rendered an important decision regarding the civil and administrative jurisdiction of the Court of Québec (CQ), a provincial court. The decision follows a reference submitted to the QCA by the Québec government in the wake of a...
“Les honoraires en demande en matière d’actions collectives : comment éviter de jouer à l’apprenti-sorcier en vue de moduler le comportement des avocats”, co-author
May 03, 2019 - Recent Developments in Québec, Canada and the United States, Vol. 455 (National Conference on Class Actions)
Read this article (in French).
University of Cambridge ‒ The William Charnley Prize in Law (2017)
Canadian Institute for Advanced Legal Studies ‒ The Right Honourable Paul Martin Sr. Scholarship (2016)
Université de Montréal ‒ The Spiegel Sohmer Award of Excellence in Tax and Commercial Law (2015); The Herbert-Marx Award of Excellence in Legal Writing (2014); The Rodolphe-Lemieux Award of Excellence in Public International Law (2014)