Mario Beaulieu, head of the St Jean-Baptiste Society, says he’s running because the only other candidate to declare so far isn’t serious enough about sovereignty.
Beaulieu says Bloc MP Andre Bellevance wants the party to be just an “advocate” for Quebec in Ottawa when it should strive for independence.
The B-Q was reduced to just four seats in the House of Commons in the 2011 election from the 49 seats it held after the 2008 vote.
Beaulieve says by focusing on independence, the party can increase the number of MPs after the 2015 election.
The Bloc Quebecois will select a new leader in late May in Rimouski to replace Daniel Paille, who stepped down last December due to health reasons.
Beaulieu also said that if he becomes leader, he would also defend the rights of francophones outside Quebec.