The Bloc Québécois, the sovereigntist party that once formed Canada's Official Opposition, is in crisis mode after seven of its 10 MPs quit.

​The party made the announcement after a caucus meeting in Ottawa on Wednesday morning, pointing to party head Martine Ouellet's leadership style as their reason for leaving.

A statement from the party said the seven will form a separate parliamentary group.

The caucus was divided into two camps: those who support Ouellet as leader and the seven who accuse her of being authoritarian.

"The crisis shaking the Bloc Québécois is bad for both the party itself and the sovereigntist movement," said the party in a French statement.

"The differences we have with our leader are unfortunately too great for a lasting peace to be envisaged."

Fall from Official Opposition to 3 MPs

One of the MPs who left is Louis Plamondon, who has been in the Commons since 1984, including the last 25 years as a Bloc MP.

"I've witnessed many crises within the Bloc Québécois and this is no doubt the deepest," Plamondon said.

The other six are:

Luc Theriault

Gabriel Ste-Marie

Rheal Fortin

Michel Boudrias

Simon Marcil

Monique Pauze

Fortin, who served as the party's interim leader between 2015 and 2017, said the departing members still believe in an independent Quebec, but the split came down to a clash over strategy.

He said the party members were fighting daily.

"Ouellet would like us to talk and talk about sovereignty, about the independence of Quebec, I will say, in every and all sentences. We believe that we have to make the real promotion by explaining why Quebec should be independent, what's the problem with the actual federal Constitution with that government and that system," he said.

The Bloc's impact on the national political scene has diminished since its heyday under Lucien Bouchard. In the 1993 election, the party secured 54 seats and formed the country's Official Opposition.