Quebec Premier François Legault addressed a letter Saturday to Prime Minister Justin Trudeau containing his proposal to reform the province’s language law and amend the Canadian Constitution.

The letter asserted that Quebec has the power to unilaterally amend the Canadian constitution to protect French is its official language. Legault wrote in the letter:

“French is at the very foundation of our identity and our culture. Quebec is the only French-speaking province in North America. Protecting the French language is one of the most important responsibilities, maybe the most important responsibility, of a Quebec premier.”

The province proposed Bill 96 Thursday, which strengthens language requirements for businesses, governments, and schools. The bill could also affect courts, education, and immigration. Legault assured Trudeau the bill respects the rights of Quebec’s English-speaking community.

The Coalition Avenir Québec (CAQ) government has pre-emptively invoked the notwithstanding clause in Section 33 of the Canadian Charter of Rights and Freedoms to shield the bill from legal challenges. The notwithstanding clause, known as the override clause, is part of the Canadian constitution which allows federal, provincial, or territorial governments to override or bypass certain Charter rights temporarily.

Trudeau’s response Wednesday was optimistic as he found it legitimate for Quebec to modify the section of the constitution that applies specifically to it as long as the anglophones’ rights in Quebec are respected.