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.
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.