Quebec's left-wing separatist party is no longer stuck on the margins of the National Assembly.

By winning ten seats in three cities, Quebec Solidaire has become the province's second opposition and knocked the Parti Quebecois into fourth place in electoral standings.

Party spokespeople Gabriel Nadeau-Dubois and Manon Massé said the slowly building success is no accident.

"People were looking at me with a little smile saying 'don't get ahead of yourself, don't be too optimistic' but we've been saying it for months that Tascherau, Jean Lesage, Sherbrooke and Rouyn-Noranda-Temiscamingue were ridings we could take," said Nadeau-Dubois.

Among the party's achievements was winning Rosemont and defeating PQ leader Jean-Francois Lisée.

"I was not going to run this campaign to focus on Jean-Francois Lisée, the leader of the PQ. I was just trying to offer something else to the people of Rosemont," said newly-elected MNA Vincent Marissal.

Political analyst Gilles Duceppe said that Quebec Solidaire gained when Lisée "made an error two years ago" and announced the PQ would not push for an independent Quebec, allowing those who cared about sovereignty to vote for Quebec Solidaire.

Massé reiterated Tuesday that her party cares very strongly about separating Quebec from the rest of Canada.

"We're still working on our proposal and of course for us the independence it's a central issue for us," said Massé.

McGill professor Antonia Maioni said the worldwide embrace of populism also helped QS.

"Let's not lose sight of the fact that most Quebecers voted for change, and they chose as vehicles for that change two populist parties that were not traditional parties," said Maioni.

Nadeau-Dubois and Massé say they now have the credibility to fight the CAQ government on key issues like electoral reform, immigration, public services and the environment.

"Quebec Solidaire will be the real official opposition to Francois Legault's government. We will be there to make sure climate change is an issue," said Nadeau-Dubois.

"Quebec Solidaire is not the little brother of the Parti Quebecois. We are not an accident in Quebec politics."