Charles, 73, became king of the United Kingdom and the head of state of 14 other nations, including Canada, when his mother, Queen Elizabeth, died in September.

There have previously been calls to change the oath in the province. But the queen's death, combined with pressure from the Parti Quebecois (PQ) and Quebec solidaire - two political parties that back Quebec's independence from Canada - have cast a bright spotlight on making it optional.

"It's a beautiful moment for Quebec democracy," said PQ leader Paul St-Pierre Plamondon on Twitter. "Another step toward the emancipation of the Quebec people from British colonialism."

The PQ's three elected lawmakers tried unsuccessfully last week to enter the legislature after declining to take the oath.