Through a simple act of Parliament.
By guaranteeing some provinces a minimum of seats on the grounds that a province cannot lose seats, they altered the principle of proportionate representation in 1985 by passing this simple act of Parliament. Was this act challenged? Yes, Mr. Speaker. Was it invalidated? No, Mr. Speaker.
In the case of Campbell v. Canada (1988) 49 DLR, 4th edition, page 321-they can write this down as good reading material-the British Columbia Court of Appeal pointed out that the protection of representation despite the decline in a province's population does not affect the principle of proportionate representation and therefore does not require amending section 41(1)( a ) of the British North America Act.