The Canadian Constitution, the supreme law of the land, allows judges to invalidate laws that are unconstitutional.
Constitutionality rulings can be thorny, as they often involve significant value judgements that pit constitutional rights against the objectives of legislatures. For example, earlier this summer a British Columbia judge gave permission for a terminally ill woman to commit suicide with the assistance of a physician. The case is currently on appeal to the B.C. Court of Appeal.
Assisted suicide is a criminal offence and physicians are deterred from providing it by current law. Justice Lynn Smith, in her ruling on the constitutionality of the prohibition on physician-assisted suicide, noted Canadians travel to Switzerland for assisted suicide at high cost and possible risk of criminal prosecution for relatives.