Open this photo in gallery NDP MP Nathan Cullen rises in the House of Commons in Ottawa on Oct. 25, 2017. Adrian Wyld/The Canadian Press

Veteran NDP MP Nathan Cullen, one of the highest-profile members of the party’s national caucus, announced Friday his exit from federal politics – the latest in a series of New Democrats to rule out seeking re-election in October.

The British Columbia member, who will have served 15 years by the time he departs this fall, played down any suggestion that his decision not to seek re-election is a blow to the party.

Thirteen members of the caucus, which now has 41 MPs, have said they will not seek re-election, raising questions about party leader Jagmeet Singh’s management of the New Democrats, who are facing challenges in such areas as the polls, fundraising and policy.

Story continues below advertisement

Mr. Cullen, 47, is the second NDP MP from British Columbia to announce his departure this week, following Victoria-area MP Murray Rankin. Earlier on this term, Burnaby-South MP Kennedy Stewart left to run for and win the office of Vancouver mayor and Nanaimo-area MP Sheila Malcolmson was elected an NDP member of the provincial legislature.

But the MP for Skeena-Bulkley Valley said that after 15 years, five elections, a leadership bid in 2011-12 and with two 8½-year-old twin boys appealing for his attention, it was time to leave.

Mr. Cullen has no specific professional plans. Asked whether he would be interested in provincial politics, he said, “I am not ruling it out, but I don’t have that as my plan right now.” The provincial New Democrats govern B.C. under Premier John Horgan.

“When my family and I have been talking, it was just to decide whether we wanted to be in federal politics after October. Yes or no, not conditional on some other opportunity or offer. It was just, ‘Let’s just be clear and clean on this,’ not have something else waiting in the wings.”

Mr. Cullen placed third behind Thomas Mulcair and Brian Topp in the 2012 leadership vote. His roles in Parliament included House leader for the Official Opposition and Opposition finance critic. Following the 2015 election, he was environment critic as well as critic for democratic reform.

He said no one, himself included, is irreplaceable. “I’ve seen irreplaceable people leave, and then they get replaced,” said Mr. Cullen, adding that since he has been musing about his future, prospective NDP candidates have been in touch about vying to represent the party in his riding.

Mr. Cullen said New Democrats have had a good week with Mr. Singh winning a by-election in Burnaby-South and finally gaining a seat in the House of Commons. Mr. Cullen has been supportive of Mr. Singh, who succeeded Thomas Mulcair in 2017. “He is humble enough to know that he has got work to do,” he said.

Story continues below advertisement

He said the shine is off the federal Liberals under Prime Minister Justin Trudeau given the scandal surrounding the government’s handling of the SNC-Lavalin affair. And he said questions around the issue may even give the party traction in Quebec, the site of the party’s Orange Wave in 2011.

“Context is everything. I don’t want to harp too much on Mr. Trudeau’s troubles, but a sponsorship-like corruption scandal hits a note different in Quebec than in other parts of the country because they have seen this movie before,” he said.

To get ahead, he said the NDP will have to be authentic and “unapologetically progressive” as well as make a blunt appeal to govern Canada.

“The old NDP was about being the conscience of the Parliament, and not happy to lose, but comfortable with the idea of being third,” he said.

He said his biggest takeaway from the 2015 election was that voters were not terrified of an NDP government though they decided otherwise. “Our offer should be to be government, and be unapologetic about it.”

Mr. Cullen said he will inevitably settle in B.C. “Ottawa is fine, but it’s better here,” he said from his riding.