Labour lawyer and arbitrator

Laskin's non-academic practice involved primarily the area of labour and employment law, where he was known to have a kind heart and worked to advance the rights of trade unions. His most significant contributions were as a grievance arbitrator, where he made one of the greatest contributions to labour jurisprudence, with many of the legal concepts he developed finding their way into the broader field of law, especially human rights law which in the early days grew largely out of disputes in the workplace.

Many of Laskin's decisions are still referenced as leading cases of Canadian labour law and the University of Toronto's Centre for the Study of Industrial Relations awards the Bora Laskin Award in Labour Law annually to two lawyers who have made an outstanding contributions to Canadian labour law (one to union-side and one to employer-side).^[12]

Ontario Court of Appeal

Laskin's career on the bench began in 1965 with his appointment to the Ontario Court of Appeal. While on the Court of Appeal, Laskin gave a decision in a divorce case, upholding the constitutional authority of the federal Parliament to include the right to spousal support under the Divorce Act.^[13][14] Laskin held that spousal support was ancillary to Parliament's constitutional jurisdiction over divorce under the Constitution Act.^[15] When the Supreme Court of Canada considered the same issue three years later, it unanimously reached the same conclusion, citing Laskin's decision from the Ontario Court of Appeal.^[16]

Supreme Court of Canada

On March 19, 1970, he was appointed on the advice of Prime Minister Pierre Trudeau to the Supreme Court of Canada, becoming the first Jewish justice to sit on that court. Again on the advice of Trudeau, Laskin was appointed Chief Justice on December 27, 1973.^[17] He held that position until his death in 1984.

Laskin's appointment as Chief Justice generated some controversy. He was the second-most junior justice on the court, having served for only three years. The long-standing tradition was that on the retirement of the chief justice, the senior puisne justice on the court would be appointed. Since the establishment of the Supreme Court in 1875, this practice had been followed except on two occasions, in 1906 and 1924, when the senior puisne justices had been passed over. By that tradition, the appointment as Chief Justice would have gone to Justice Ronald Martland, who had been on the court for fifteen years. When Prime Minister Trudeau appointed Laskin, it was said that Justice Martland had been given very little notice that he would be passed over, and was upset by it. Minister of Finance John Turner was rumoured to be furious at the departure from the traditions of the court.^[18]

Judicial philosophy

Laskin was a liberal jurist who often found himself on the minority side of decisions. His specialty was labour law and constitutional law and he had a reputation as a civil libertarian.

On matters of federalism under the Constitution Act, 1867, Laskin has been considered the most aggressive supporter of the federal powers of any justice since Confederation. This made for a stark contrast with fellow Justice Jean Beetz, who was known as one of the strongest supporters of provincial powers under the Constitution.

In his earlier years on the Supreme Court, Laskin was frequently in dissent. During the 1970s, Laskin frequently joined with justices Wishart Spence and Brian Dickson on cases involving civil liberties, often in dissent from the more conservative majority on the court. The grouping was colloquially referred to as the "LSD connection."^[9]

Laskin often took a position that was later adopted by a majority of the court. Among his most famous dissents was his opinion in Murdoch v. Murdoch, where he was the sole judge who would have ruled in favour of a wife's application for an equal division of property acquired during the course of the marriage.^[19] The outcome of the case was highly controversial. It triggered reforms to matrimonial laws across the country, adopting Laskin's view of property equality between husband and wife. Years later, Laskin said that the position he took in this case was the likely cause of his promotion to Chief Justice over the more senior Ronald Martland.

The Patriation Reference

Laskin presided over a number of landmark constitutional cases, most notably the 1981 Patriation Reference, which considered Pierre Trudeau's attempt to have the federal government unilaterally patriate the Constitution of Canada without the consent of the provinces. The case was a consolidated appeal of three provincial references, from Quebec, Manitoba and Newfoundland. By a 7-2 division, a majority of the court held that Parliament had the legal authority to act unilaterally. However, by a division of 6-3, the court also held that unilateral federal action would violate a constitutional convention that had emerged since Confederation, requiring substantial provincial agreement on constitutional amendments. Laskin was one of the judges in the majority on the issue of Parliament's legal authority to act unilaterally, but was one of the three dissenting judges who would have held that there was no constitutional convention restricting Parliament's power to act unilaterally.^[20]

As a result of the decision in the Patriation Reference, Trudeau decided to begin a new round of negotiations with the provinces, which resulted in the patriation of the Constitution from Britain being agreed to by all provinces save Quebec. Historian Frederic Bastien suggests that Laskin may have violated the constitutional separation of powers by discussing the deliberations of the court with politicians, casting doubt on the legitimacy of the decision.^[21] However, surviving participants in the Reference process do not think that the allegations, even if true, undercut the validity of the court's decision. Other scholars said that the patriation process violated judicial independence.^[22]