Founder Lucien Bouchard had been a cabinet minister in the federal Progressive Conservative government of Brian Mulroney.

The Bloc seeks to create the conditions necessary for the political secession of Quebec from Canada and campaigns exclusively within the province during federal elections.

Due to the 2019 and 2021 elections resulting in a Liberal minority government, the Bloc shares the balance of power with the New Democratic Party.

[26][27][28] The Bloc Québécois was formed in 1990 as an informal coalition of Progressive Conservative and Liberal Members of Parliament from Quebec, who left their original parties around the time of the defeat of the Meech Lake Accord.

[29] The initial coalition that led to the Bloc was headed by Lucien Bouchard, who had been federal Minister of the Environment in the Progressive Conservative government of Brian Mulroney.

[29] Bouchard abandoned the government in May 1990 in response to the report of a commission headed by Jean Charest that suggested changes to the Meech Lake Accord.

Bouchard was joined by five of his fellow Tories (Nic Leblanc, Louis Plamondon, Benoît Tremblay, Gilbert Chartrand, and François Gérin), along with two Liberals (Gilles Rocheleau and Jean Lapierre).

The first Bloquiste candidate to be elected was Gilles Duceppe, then a union organizer, in a by-election for the Montreal riding of Laurier—Sainte-Marie on 13 August 1990.

[31] Soon after the 35th Parliament convened, Bouchard announced that Bloquiste MPs would only speak French on the floor of the House of Commons, a policy that remains in force to this day.

The election of such a relatively large number of Bloquistes was the first of The Three Periods, a plan intended to lay out the way to sovereignty created by PQ leader Jacques Parizeau.

[34] It revived René Lévesque's notion that the referendum should be followed by the negotiating of an association agreement between an independent Quebec and the rest of Canada.

In the wake of the referendum defeat, Gauthier proved unable to hold the fractious caucus together and resigned as leader just one year later.

[40][41] In the 1997 federal election, the Bloc Québécois dropped to 44 seats, losing official opposition status to the Reform Party.

Then, in February 2004, the Auditor General of Canada uncovered the sponsorship scandal, suggesting illegality in the spending of federal monies in Quebec in support of Canadian unity.

As well, the Liberal government of Jean Chrétien passed party financing legislation that resulted in the Bloc receiving millions of dollars in subsidies that helped to stabilize its organization.

There was persistent speculation as to the possibility of the Bloc forming alliances with other opposition parties to wrest the government away from the Conservatives.

[citation needed] Gilles Duceppe announced on 11 May 2007 that he would run for the leadership of the Parti Québécois to replace André Boisclair, who resigned on 8 May 2007, after the poor performance in the March 2007 Quebec provincial election and internal dissent forced him to step down.

[47] The Bloc made slight gains following the 2008 federal elections as they won 49 seats, one more than the number they had before the previous parliament was dissolved.

In a speech in front of his supporters following the election, BQ leader Gilles Duceppe claimed to have achieved his objectives, adding: "without the Bloc Québécois tonight, Mr. Harper would have formed a majority government".

[51] On 9 September 2004, the three signed a letter addressed to then-Governor General Adrienne Clarkson, stating, We respectfully point out that the opposition parties, who together constitute a majority in the House, have been in close consultation.

[51]On the same day the letter was written, the three party leaders held a joint press conference at which they expressed their intent to co-operate on changing parliamentary rules, and to request that the governor general consult with them before deciding to call an election.

However, at the time, Harper and the two other opposition leaders denied trying to form a coalition government, despite the letter written to the governor general.

He defeated BQ Member of Parliament André Bellavance, who had campaigned on a platform of broadening the Bloc beyond being a coalition of sovereigntists and had been endorsed by the rest of the party's caucus.

[65] On 25 August 2014, former interim parliamentary leader and failed leadership contender André Bellavance also resigned, reducing the Bloc to two MPs – one of whom, Claude Patry, had announced that he would not run for re-election.

[66] On 31 December 2014, the party's vice president, Annie Lessard, resigned after a personality conflict with leader Mario Beaulieu.

On 28 February 2018, seven of the Bloc's ten MPs quit the party's caucus to form the Groupe parlementaire québécois (later called Québec debout) citing conflicts with Ouellet's leadership style and her insistence that the Bloc should emphasize promoting Quebec independence over "defending Quebec's interests".

[74][75] Three MPs remained in the Bloc's caucus: Mario Beaulieu (La Pointe-de-l'Île), Xavier Barsalou-Duval (Pierre-Boucher—Les Patriotes—Verchères), and Marilène Gill (Manicouagan).

[77] A Léger Marketing poll conducted shortly after put the Bloc Quebecois at 12% among Quebec voters, its lowest rating ever.

[85] Since Blanchet became leader the BQ has seen their support increasing in Quebec during the 2019 federal election which some considered to have exceeded expectations.

Notwithstanding his previous ties to both parties, Beaulieu has been critical of what he sees as a too timid approach to sovereignty by both the Bloc and PQ.