Lalonde, who represented the Bloc in the Commons between 1993 and 2011, also served as a cabinet minister in the Parti Quebecois government of Rene Levesque in the 1980s.
She announced in 2010 she would not seek re-election so she could fight her cancer. Lalonde was elected in the Montreal riding of Mercier in 1993, 1997 and 2000 and in La Pointe-de-l'Ile in 2004, 2006 and 2008.
Former Bloc leader Gilles Duceppe described Lalonde on Friday as "an admirable woman" who was also a friend.
"Of course, she was a fighter for sovereignty but also, for nine years, she fought cancer," he said in an interview. "She overcame unbelievable obstacles throughout her years."
Duceppe also underlined Lalonde's work fighting for sovereignty on the international scene, adding she tried to do that in a very positive and dignified way.
NDP Leader Thomas Mulcair offered his condolences to Lalonde's family on Twitter, describing her as "a courageous and determined person who fought for her community."
Prime Minister Stephen Harper also offered sympathy to the family and friends of the former parliamentarian and Quebec cabinet minister in a one-line tweet.
Bloc MP Louis Plamondon called Lalonde a pioneer in the debate on the right to die with dignity.
In 2005, she introduced legislation that would have legalized assisted suicide in Canada, but it was later rejected by a majority of MPs in the House of Commons.
"The proposed legislation she tabled and defended more than once in Ottawa instigated this great social debate, which now has a consensus in the (Quebec) national assembly," Plamondon added.
In an earlier interview with The Canadian Press, Lalonde explained that her right-to-die proposal grew out of a profound conviction and "a need for justice."
Quebec's Bill 52 essentially outlines the conditions necessary for someone to get medical assistance to die and spells out the requirements necessary before a doctor can accept.
It cleared clause-by-clause study in the legislature this week and is expected to become law once the national assembly reconvenes next month.
Described as a pragmatic sovereigntist, Lalonde maintained that the independence option would be good —not only for Quebec — but also for the rest of Canada.
"We would stop arguing and would be able to work in collaboration (with each other)," she once said.
Lalonde became a non-elected minister responsible for the status of women when she was first recruited by then-premier Levesque in 1985. But she quit the post a few months later after she failed to beat former premier Robert Bourassa in June of that year in what was his comeback byelection.
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