Sub-national branches of the NDP have formed the government in six provinces (Ontario, Manitoba, Saskatchewan, Alberta, British Columbia, and Nova Scotia) and the territory of Yukon.

Since 2017, the NDP has been led by Jagmeet Singh, who is the first visible minority to lead a major federal party in Canada on a permanent basis.

In 1961, at the end of a five-day long founding convention which established its principles, policies and structures, the New Democratic Party was born, and Tommy Douglas, the long-time CCF Premier of Saskatchewan, was elected as its first leader.

[23] At the 1971 leadership convention, an activist group called the Waffle tried to take control of the party but was defeated by David Lewis with the help of the union members.

Together, they succeeded in passing several socially progressive initiatives into law such as pension indexing and the creation of the crown corporation Petro-Canada.

Under Ed Broadbent (1975–1989) the NDP attempted to find a more populist image to contrast with the governing parties, focusing on more pocketbook issues than on ideological fervour.

The Liberals, however, had reaped most of the benefits of opposing the Canada–United States Free Trade Agreement to emerge as the dominant alternative to the ruling PC government.

The loss was blamed on the unpopularity of NDP provincial governments under Bob Rae in Ontario and Mike Harcourt in British Columbia and the loss of a significant portion of the Western vote to the Reform Party, which promised a more decentralized and democratic federation along with right-wing economic reforms.

The party was able to harness the discontent of voters in Atlantic Canada, who were upset over cuts to employment insurance and other social programs implemented by Jean Chrétien's Liberal majority government.

[citation needed] In the November 2000 election, the NDP campaigned primarily on the issue of Medicare but lost significant support.

The governing Liberals ran an effective campaign on their economic record and managed to recapture some of the Atlantic ridings lost to the NDP in the 1997 election.

[citation needed] McDonough announced her resignation as party leader for family reasons in June 2002 (effective upon her successor's election).

As has been the case with Liberal minorities in the past, the NDP were in a position to make gains on the party's priorities, such as fighting health care privatization, fulfilling Canada's obligation to the Kyoto Protocol, and electoral reform.

[citation needed] On November 9, 2005, after the findings of the Gomery Inquiry were released, Layton notified the Liberal government that continued NDP support would require a ban on private healthcare.

When the Liberals refused, Layton announced that he would introduce a motion on November 24 that would ask Martin to call a federal election in February to allow for several pieces of legislation to be passed.

On November 28, 2005, Conservative leader Stephen Harper's motion of no confidence was seconded by Layton and it was passed by all three opposition parties, forcing an election.

This included a breakthrough in the riding of Edmonton-Strathcona, only the second time the NDP had managed to win a seat in Alberta in the party's history.

[citation needed] In the 2011 federal election, the NDP won a record 103 seats, becoming the Official Opposition for the first time in the party's history.

[citation needed] In July 2011, Layton announced that he was suffering from a new cancer and would take a leave of absence, projected to last until the resumption of Parliament in September.

[32] On October 1, 2017, Jagmeet Singh, the first person of a visible minority group to lead a major Canadian federal political party on a permanent basis, won the leadership vote to head the NDP on the first ballot.

[34] Alexandre Boulerice, who was elected to his third term in Rosemont—La Petite-Patrie, was the only NDP candidate to win a seat in Quebec,[35] while the party lost all three of its Saskatchewan ridings (Desnethé—Missinippi—Churchill River, Regina—Lewvan, and Saskatoon West) to the Conservatives.

[36] The party remained shut out of Toronto[37] and lost two of its MPs (Cheryl Hardcastle in Windsor—Tecumseh and Tracey Ramsey in Essex) in the rest of Ontario,[38] while making small or no gains in the popular vote in Manitoba, Newfoundland and Labrador, Alberta and Nunavut.

[39] Following the election, the NDP held the balance of power as the Liberals won a minority government, although it fell back to fourth place behind the resurgent Bloc Québécois.

[40][41] During the COVID-19 pandemic, the NDP used its leverage to lobby the Liberals to be more generous in their financial aid to Canadians, including by extending of the Canada Emergency Response Benefit (CERB) program, which was a key demand in order to provide confidence to the government in the autumn of 2020.

[42] In the snap 2021 federal election, the NDP made minor gains in both vote share and seat count, winning in 25 ridings.

[43] These gains were offset by losses to the Liberals in St. John's East and Hamilton Mountain, where incumbent NDP MPs Jack Harris and Scott Duvall did not stand for re-election.

[46] In March 2022, the NDP agreed to a confidence and supply deal with the Liberal Party, led by Prime Minister Justin Trudeau.

It has broadened to include concerns of the New Left, and advocates issues such as LGBT rights, international peace, and environmental stewardship.

The NDP governs the provinces of British Columbia and Manitoba, forms the Official Opposition in Alberta, Saskatchewan, and Ontario, and has sitting members in every provincial legislature except those of Quebec, New Brunswick, and Prince Edward Island.

The NDP has previously formed the government in the provinces of Alberta, Ontario, Saskatchewan, British Columbia, Nova Scotia and the Yukon Territory.