Mourani, who has been sitting as an Independent MP since she quit the separatist party after being booted from the Bloc caucus in September, told Radio-Canada on Wednesday that after much reflection she has come to the conclusion that the federal system is better placed to protect the rights of Quebecers.
"What better to protect us than the Canadian Charter of Rights and Freedoms," Mourani said.
In an open letter made public Wednesday, Mourani explained that "the ease with which Quebec's Charter of Human Rights and Freedoms can be modified, even abolished, has convinced me of the relevance of the Canadian federal system."
"I have come to the conclusion that my belonging to Canada, with its Charter of Rights and Freedoms, better protects the Quebec identity of all Quebec citizens."
"I am no longer a sovereigntist," Mourani said.
The former Bloc MP told Radio-Canada the title of her open letter, "To Protect Our Homes and Our Rights," is indeed a nod to Canada's national anthem.
Mourani said she will continue to represent the constituents of Ahuntsic as an Independent MP, but did not rule out running for another federalist party in the next election.
During a year–ender press conference in Ottawa earlier in the day, NDP Leader Tom Mulcair was asked whether Mourani's political future would include joining the NDP.
Mulcair said the NDP's stance against MPs crossing the floor is clear, and if Mourani wants to join the NDP, she'll have to seek membership and run under that banner in the next federal election.
"This is something that we strongly believe in. It's not a whim. It's a really strong question of principle for us."
The NDP called on Ontario MP Bruce Hyer to resign his seat after he announced he was joining the Green Party, last Friday.
Hyer was elected as an NDP MP but left the caucus almost two years ago to sit as an Independent MP after party discipline required him to vote against the abolition of the gun registry, something the MP felt he could not do.
Mulcair, who resigned from Jean Charest's cabinet in 2006, conceded he did call Mourani after she quit the Bloc.
"I did call her once after she left because these are very tough moments — I went through one myself in my provincial career — just to commiserate and tell her I was thinking of her."
The NDP leader added that "anybody abandoning the idea of breaking up Canada is good news."
Mourani told Radio-Canada she has not been asked to join any federal party.
Daniel Paillé, the leader of the Bloc Québécois, announced his resignation on Monday citing health issues.
Paillé did not have a seat in the House of Commons.