Politics Economy The Act to Protect the Province Against Communistic Propaganda (French: Loi protégeant la province contre la propagande communiste), commonly known as the "Padlock Law" or "Padlock Act" (French: La loi du cadenas), was a law in the province of Quebec, Canada that allowed the Attorney General of Quebec to close off access to property suspected of being used to propagate or disseminate communist propaganda.

[1] The law was introduced by the Union Nationale government of Maurice Duplessis and made it illegal to "use [a house] or allow any person to make use of it to propagate Communism or Bolshevism by any means whatsoever".

This included printing, publishing or distributing of "any newspaper, periodical, pamphlet, circular, document or writing, propagating Communism or Bolshevism".

Violations of the Act subjected such property to closure by the Attorney General, including the locking of access doors with padlocks, against any use whatsoever for a period of up to one year and any person found guilty of involvement in prohibited media activities could be incarcerated for three to thirteen months.

[6] In their concurrence, justices Ivan Rand, Roy Kellock and Douglas Abbott also argued the law was ultra vires because it contravened an implied bill of rights that underlies the Canadian constitution, but this view was not shared by the rest of the majority.