The Bloc Québécois plans to introduce a bill Thursday that would require anyone applying for Canadian citizenship in Quebec to demonstrate functional proficiency in French.

Bloc Leader Yves-François Blanchet says that familiarity with the official language of Quebec is essential in the face of what he calls an ongoing threat to the mother tongue of most Quebecers.

Currently, most applicants must demonstrate a professional proficiency in either English or French to qualify for citizenship. The proposed legislation comes after Montreal Liberal MP Emmanuella Lambropoulos told the House of Commons official languages committee last week that the idea of a French-language decline is a "myth."

She reversed her comments after a social media backlash, saying in a statement Saturday her remarks were "insensitive," that French is in decline and that she hopes to find ways to protect it.

Blanchet said some Liberals threw Lambropoulos "under the bus" by calling her out for her initial remarks, and suggested the governing party was hypocritical in its professed concern for the state of the French language.