Flags have been lowered to half-mast at the National Assembly to mark the death of Sylvie Roy, the MNA for Arthabaska.

She was hospitalized at the beginning of July following what her office calls "a serious illness," which a family friend later confirmed was acute hepatitis.

Her medical condition never improved, and she passed away on Sunday afternoon at the Enfant-Jesus hospital in Quebec City.

News of her death sent shockwaves through the political spectrum in the province.

“She was a pretty well-respected member of Parliament. She was straight-talking, she was a fighter and pretty popular in her constituency,” said PQ MNA Pascal Berube.

Roy first entered politics in 1998 as mayor of Saint Sophie de Levrard, a small town near Quebec City.

In 2003 she shifted to provincial politics, and was elected to the National Assembly as a member of the Action Democratique du Quebec.

She became interim leader of the ADQ in 2009, and was re-elected in 2002 as a member of the CAQ following the merger of the two parties.

Mario Dumont, the founder of the ADQ, said he had the utmost respect for Roy.

"From the very beginning I always had a lot of admiration for her. She was a person of infinite determination. Whether it was to win locally in a riding, whether it was to push on issues. Things that were important to her, she would never give up," said Dumont.

He said she was always an advocate for those who did not have a voice.

"Victims of criminal acts. The kids who were victims. She would say they don't have a big lobby, they don't have a big union," said Dumont.

"As a person with access to microphones she would give that voice to people you never hear."

Roy left the CAQ last year after an argument with leader Francois Legault.

Roy was the first MNA, and one of the most vocal, to call for an inquiry into corruption in the province's construction industry.

She continued to push that issue for 948 days, until then premier Jean Charest agreed to call an inquiry to examine the links between construction, the political class, and crime. Roy is credited with helping trigger the launch of the Charbonneau Commission.

Roy was 51 years old.