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Appellate Advocacy

Appeals carry exceptional stakes. An appeal decision can reshape your business, set precedent, or put years of work at risk. When bringing an appeal or defending a hard-won victory, you need experienced appellate lawyers who understand how to win at every level of court in Canada. We help clients preserve issues, position the record, and build a foundation for appellate success from the outset.

Our appellate litigation team

BLG is home to the largest appellate litigation practice in Canada, with a national footprint spanning Toronto, Ottawa, Vancouver, Calgary and Montréal.

Our award-winning, 75-member team is led by Laura M. Wagner and Teagan Markin, Partners and Co-Chairs of BLG's Appellate & Public Advocacy Groups. Both Laura and Teagan are ranked by Chambers for Litigation: Administrative & Public Law. Together with the team, they represent clients before appellate courts, tribunals and administrative decision-makers across Canada.

Recognized excellence at the highest level

Guy Pratte and Nadia Effendi are among Canada's most sought-after and distinguished appellate advocates, reflecting the depth and strength of BLG's nationally recognized appellate and public law team. Both are ranked Band 1 by Chambers Canada in Litigation: Administrative & Public Law and Constitutional Law.

Guy is an award-winning advocate with extensive experience in complex commercial litigation, including class actions, as well as administrative and constitutional law. He is widely recognized for his leadership on some of Canada's most significant litigation and public law matters.

Nadia represents a wide range of clients in complex and often high-profile proceedings, including class actions and administrative, regulatory, constitutional and human rights law disputes. She received the 2025 Catzman Award for Professionalism and Civility, reflecting both her legal excellence and professional leadership.

The insight of judicial experience

Our appellate practice is further distinguished by the insight of former appellate and Supreme Court of Canada justices, including the Honourable Thomas Cromwell, the Honourable Marina Paperny, the Honourable Jacques Fournier, the Honourable Ed Chaisson, and the Honourable Dennis O’Connor. They work alongside Chambers ranked counsel, Best Lawyers honourees, and Benchmark Litigation Stars to deliver strategic, informed advocacy at every level of court.

Our national appellate litigation team helps you:

Integrate appellate strategy from day one. We bring appellate thinking to building the record, framing the argument, and setting litigation strategy from the outset, materially changing the available outcomes on appeal.
Navigate critical decision points. We advise on when to appeal a court decision, whether to change counsel, how to narrow issues for maximum impact, and when a shift in strategy is needed.
Access the judicial perspective. Our former Supreme Court and appeal court justices provide insights on what makes a successful appeal, how appellate panels evaluate arguments, and how to prepare effectively.
Execute with precision. We focus on what the court needs to see, home in on the most compelling arguments, and combine clear written advocacy with persuasive oral argument.

The result: Your appeals benefit from sophisticated strategic positioning, judicial insight, and courtroom excellence that protects your business and advances your goals.

Facing an appeal? We can advise

The strongest appeals start at trial, not after judgment. Early involvement of appellate counsel helps preserve issues, protect the record, and avoid decisions that limit appeal options. If judgment has already been issued, consult an appellate lawyer immediately to protect deadlines and strengthen your position. Our appellate litigators assist clients across Canada, including Toronto, Vancouver, Calgary, Ottawa, and Montréal.

That decision depends on the legal errors at issue, the complexity of the appeal, and whether specialized appellate expertise or a fresh perspective will improve your case. Courts are neutral about changes in counsel. Results depend on the quality of advocacy, not continuity. In many cases, the most effective approach is adding appellate specialists to support trial counsel who know the record.

Effective appeals focus on identifying one or two strong grounds rather than a long list of issues. Written factums carry the most weight, while oral argument allows counsel to respond directly to the panel’s concerns. Strategic preparation may include mock appeals, targeted input from senior appellate counsel or former judges, and careful balancing of subject matter knowledge with appellate advocacy skills.

Our appellate lawyers appear at all levels, including before the Supreme Court of Canada, provincial and territorial courts of appeal, the Federal Court of Appeal and administrative tribunals. We handle constitutional and Charter appeals, administrative law matters, commercial and civil litigation appeals, regulatory disputes, and criminal appeals nationwide.

BLG's appellate lawyers have the experience to assist with:

Appeals to all levels of court
Pre-trial advisory on preserving appellate issues
Leave applications and intervention strategies
Strategic counsel selection and team composition
Mock appeal design and execution
Post-judgment appeal risk assessment

Supreme Court of Canada appeals

Lord Reading Law Society and Attorney General of Canada in a Supreme Court of Canada challenge to Québec's Bill 21, which restricts religious symbols in public service. The case raises fundamental questions on minority rights, religious freedom, and the limits of the notwithstanding clause. The ruling will have lasting constitutional impact.
Attorney General of Canada in securing Supreme Court of Canada constitutional victory in carbon reference cases, establishing federal jurisdiction over climate change as matter of national concern, and affirming Greenhouse Gas Pollution Pricing Act validity against provincial opposition.
Law Society of Upper Canada in a landmark Supreme Court victory upholding its decision to deny accreditation to Trinity Western University's law school. The ruling clarified constitutional rights, human rights, and administrative law principles, reinforcing the Law Society's authority as a regulator.
Centre for Free Expression at TMU in interventions before the Superior Court, the Court of Appeal for Ontario, and the Supreme Court of Canada challenging the constitutionality of amendments to Ontario's Election Finances Act. The Supreme Court's decision now stands as a leading case on the right to vote under section 3 of the Charter.
Canadian Civil Liberties Association as intervenor in a landmark Supreme Court of Canada case balancing freedom of expression, and human rights. The case, involving comedian Mike Ward's controversial act, set key precedents on when artistic expression can be legally restricted.
Canadian Civil Liberties Association in a Supreme Court of Canada case on statutory appeal rights under the Immigration and Refugee Protection Act. The case challenges a restrictive interpretation that limits access to appeals. The ruling could reshape procedural fairness and Charter protections in immigration law. Decision pending.

Lord Reading Law Society and Attorney General of Canada in a Supreme Court of Canada challenge to Québec's Bill 21, which restricts religious symbols in public service. The case raises fundamental questions on minority rights, religious freedom, and the limits of the notwithstanding clause. The ruling will have lasting constitutional impact.
Attorney General of Canada in securing Supreme Court of Canada constitutional victory in carbon reference cases, establishing federal jurisdiction over climate change as matter of national concern, and affirming Greenhouse Gas Pollution Pricing Act validity against provincial opposition.
Law Society of Upper Canada in a landmark Supreme Court victory upholding its decision to deny accreditation to Trinity Western University's law school. The ruling clarified constitutional rights, human rights, and administrative law principles, reinforcing the Law Society's authority as a regulator.
Centre for Free Expression at TMU in interventions before the Superior Court, the Court of Appeal for Ontario, and the Supreme Court of Canada challenging the constitutionality of amendments to Ontario's Election Finances Act. The Supreme Court's decision now stands as a leading case on the right to vote under section 3 of the Charter.
Canadian Civil Liberties Association as intervenor in a landmark Supreme Court of Canada case balancing freedom of expression, and human rights. The case, involving comedian Mike Ward's controversial act, set key precedents on when artistic expression can be legally restricted.
Canadian Civil Liberties Association in a Supreme Court of Canada case on statutory appeal rights under the Immigration and Refugee Protection Act. The case challenges a restrictive interpretation that limits access to appeals. The ruling could reshape procedural fairness and Charter protections in immigration law. Decision pending.

Courts of Appeal

Amazon.com.ca ULC and AMZN Mobile LLC in defending Federal Court of Appeal challenge to proportionality standards governing Competition Act section 11 production orders, protecting decade-long judicial review framework against Commissioner of Competition's overbroad information request.
NSUS Limited and NSUS Group Inc., which own and operate online poker platforms under the GGPoker and GGPoker.ca brands, in intervening in a reference on iGaming initiated by the Ontario government. NSUS supports Ontario's position that its regulated online gaming model complies with the Criminal Code. The Ontario Court of Appeal held that the model is lawful. The matter is now before the Supreme Court of Canada. The decision will determine the scope of provincial authority over online gambling and could shape the future of iGaming in Canada.
B.C. Civil Liberties Association, as intervenor, in a precedent-setting climate case before the Ontario Court of Appeal. Mathur v. Ontario challenges government accountability in climate policy and could shape future Charter litigation on environmental rights.
Canadian Airports Council in a Federal Court of Appeal case on whether local airport authorities must meet the same bilingual service obligations as federal institutions under the Official Languages Act. The ruling will impact language rights and service standards at 22 airports across Canada. Decision pending.
Canadian National Railway Company in a Federal Court of Appeal case challenging the Canadian Transportation Agency's interpretation of its interswitching rate-setting authority under the Canada Transportation Act. The court overturned the Agency's long-standing approach to interswitching rates which failed to take into account comparative market data.

Amazon.com.ca ULC and AMZN Mobile LLC in defending Federal Court of Appeal challenge to proportionality standards governing Competition Act section 11 production orders, protecting decade-long judicial review framework against Commissioner of Competition's overbroad information request.
NSUS Limited and NSUS Group Inc., which own and operate online poker platforms under the GGPoker and GGPoker.ca brands, in intervening in a reference on iGaming initiated by the Ontario government. NSUS supports Ontario's position that its regulated online gaming model complies with the Criminal Code. The Ontario Court of Appeal held that the model is lawful. The matter is now before the Supreme Court of Canada. The decision will determine the scope of provincial authority over online gambling and could shape the future of iGaming in Canada.
B.C. Civil Liberties Association, as intervenor, in a precedent-setting climate case before the Ontario Court of Appeal. Mathur v. Ontario challenges government accountability in climate policy and could shape future Charter litigation on environmental rights.
Canadian Airports Council in a Federal Court of Appeal case on whether local airport authorities must meet the same bilingual service obligations as federal institutions under the Official Languages Act. The ruling will impact language rights and service standards at 22 airports across Canada. Decision pending.
Canadian National Railway Company in a Federal Court of Appeal case challenging the Canadian Transportation Agency's interpretation of its interswitching rate-setting authority under the Canada Transportation Act. The court overturned the Agency's long-standing approach to interswitching rates which failed to take into account comparative market data.