Mourani, now an independent MP, was expelled from the Bloc caucus in September and subsequently quit the party entirely over her opposition to the secular charter proposed by the provincial Parti Québécois.
This week Mourani said she no longer considered herself a sovereigntist.
The group of 29 self-described activists took issue with her leaving the movement for Quebec independence.
The members of the group issued a letter Thursday criticizing the MP for putting all sovereigntists “in the same basket,” saying in reality, many members of the Quebec sovereignty movement oppose the secular charter.
“More than ever, in this time of confusion created by the Parti Québécois and its charter, we need your voice,” the letter reads.
The letter was signed by, among others, former Québec Solidaire candidate Alexandre Leduc, former Bloc MP Jean Dorion, University of Montreal philosophy professor Michel Seymour and feminist and activist Léa Clermont-Dion.