Interim NDP leader Nycole Turmel says she's a federalist, despite having had links to two sovereigntist parties and being a member of one as recently as Tuesday.

Just days after being named interim NDP leader, Turmel found herself on the defensive and explaining her involvement with parties other than the one she was elected to represent on May 2. NDP Leader Jack Layton is taking time off to battle cancer and he hand-picked Turmel to replace him.

Turmel held a membership with the Bloc Québécois until January of this year, and also held a membership in the left-wing, pro-sovereignty provincial party Québec Solidaire until Tuesday.

She would "let go" of her membership in Québec Solidaire, the NDP said Tuesday, soon after Turmel admitted she belonged to the party.

Turmel acknowledged that she held a membership in the provincial party while she was defending her past ties to the Bloc Québécois. She gave up her Bloc membership card weeks before announcing she would run for a seat in the House of Commons for the NDP, a party she has belonged to for more than 20 years.

Turmel said she joined the Bloc Québécois in 2006 to support a friend but that she is a federalist and that her loyalty lies with the NDP.

The former union leader said in an interview with Rosemary Barton that she doesn't support the Quebec sovereignty movement but acknowledged that she not only had a Bloc Québécois membership but one also with Québec Solidaire.

"It's not a federalist party but … at the same time they work on issues for Quebec families, in Quebec," the NDP MP for Hull-Aylmer said early Tuesday afternoon in an interview for CBC's Power & Politics.

Named interim leader 5 days ago

Turmel is a rookie MP who was elected caucus chair by the 103-member caucus and was unanimously supported by them to lead the party while Layton is away. The NDP's federal council agreed with them, and officially named her interim leader last Thursday.

Turmel said NDP officials knew about her other party memberships because she disclosed them on a questionnaire that must be completed by prospective candidates. Her links to sovereigntists also came up during the campaign and her fellow MPs would have been aware that she was questioned about them, she said.

"The caucus was aware of that. Were they aware of the card? I don't know," she said in an interview Tuesday with CBC News.

Turmel said she joined the party in 2006 in order to support her friend, former Bloc Québécois MP Carole Lavallée.

"I was friends with Carole Lavallée who was an MP with the Bloc Québécois, so I took a membership card with her in her riding," Turmel said. She said she never supported the BQ's sovereignty goals.

"I am a strong federalist, working for Canadians all over Canada," she said, "And I got the support of my caucus, the support of the federal council to represent them."

Lavallée was defeated in the May 2 election in her Saint-Bruno–Saint-Hubert riding, which she had represented since 2004. She lost to the NDP candidate, Djaouida Sellah.

Never voted for the Bloc

Turmel told CBC News she has never voted for the Bloc Québécois and that if Lavallée had been a Conservative, she would not have taken out a membership.

The interim leader said she worked with the Bloc Québécois, as well as the NDP, in her job as leader of the Public Service Alliance of Canada, a position she held until 2006. She said there are Bloc Québécois policies she agrees with, but not the one on national unity, and she made that clear to Lavallée when she joined the party.

"I really like the support they gave to the workers, as the NDP did," she said. "I cannot endorse the sovereignty, I'm working for the Canadians, all together, for families."

"And Jack Layton said it many times, we have to work with all the parties that are supporting our values, our principles, to advance the cause of Canadians to create a better life for everybody. So that was the intent but at the same time I gave my support to Carole ... I gave it to her at the time and I just resigned, I just sent back my card as soon as I decided to run for the NDP," she said.

Turmel, one of many rookie MPs in the NDP's 103-member caucus, and one of 59 MPs from Quebec, defeated Liberal Marcel Proulx in the Ottawa-area riding.

The 68-year-old former union leader has been a member of the NDP for more than 20 years and served on its federal council in the 1990s.

She told CBC News she thought she could have memberships in two parties. Holding more than one membership in a national party is contrary to the NDP's rules.

Turmel told Rosemary Barton on Power & Politics that her dual memberships in a federalist party and a sovereigntist party could be seen as "confusing" but where she stands on national unity is clear to her.

"I am a federalist, I represent Canadians," she said. "My first position, my priority, is to work for the NDP," she later added.

But Bloc Québécois MP Louis Plamondon said Turmel's explanation for joining his party makes little sense.

"Me, I have a lot of friends who are Liberals and Conservatives but never I think to take the membership card of these two parties," he said.

Conservative MP Chris Alexander says the memberships raise questions about Turmel's credibility on sovereignty issues.

"It calls into question her credibility certainly on issues of national unity and it may raise wider questions for the NDP as the official opposition," he said.

Alexander says having a party membership is a stronger statement than voting for a party, and the fact that Turmel also donated to the Bloc further undermines her defence.

"Leaders need to show good faith with voters. They need to describe what they stand for now and what they've stood for in the past. She's clearly been lacking on a couple of those fronts because this didn't come up in the election campaign."