Supreme Court Reference on Quebec Secession
On September 30, 1996, the Attorney General of Canada referred three questions pertaining to Quebec secession to the Supreme Court of Canada. On August 20, 1998, the Supreme Court answered these questions by issuing an opinion. It concluded that the National Assembly, legislature or government of Quebec do not have, either under Canadian law or international law, the right to effect the secession of Quebec from Canada unilaterally.
The link below contains a number of documents on this issue, compiled by the Canadian Department of Justice.