Nycole Turmel has accepted her party's call to lead the New Democrats while Jack Layton is seeking treatment for cancer.

Turmel was confirmed as the interim NDP leader on Thursday morning, a day after the caucus offered her their unanimous support for the job.

Speaking to reporters in Ottawa Thursday morning, Turmel said she believed she was "strong enough" to take the reins of the party while Layton is away seeking treatment for his illness.

"I'm honoured by the confidence the council has shown in me as well as my team and Jack Layton," Turmel said.

"I clearly have big shoes to fill, but I'm also fortunate to be standing on such a solid foundation.

"Jack Layton has spent eight years building this New Democrat movement for a better Canada, eight years building a team that is ready to tackle any circumstance with hope and optimism.

"That's exactly what you can expect from us in the coming weeks."

The New Democrats moved to rapidly appoint an interim leader after Layton announced Monday that he has been diagnosed with a new cancer and must take a leave of absence to attend to his health.

When Layton made the announcement about his health, he named Turmel as the person he would like to see take over his duties.

Turmel is a retired union leader who was elected to the House of Commons for the first time in the recent May election. She also is the chair of the NDP's parliamentary caucus.

After Layton, Turmel becomes the seventh person to lead the NDP.

Despite the strong support Turmel has seemingly received from the party, some parliamentarians are grumbling that she does not have the temperament to be a thorn in the side of the government.

But CTV's Ottawa Bureau Chief Robert Fife reports that these dissenting New Democrats did not openly express their views during Wednesday's caucus meeting because of the circumstances surrounding Turmel's ascension to the job.

"Nobody wanted to raise objections for the obvious reasons that it would have seemed unseemly to do so, particularly when Mr. Layton was listening in (to the Wednesday caucus meeting)," Fife told CTV's Canada AM from Ottawa on Thursday morning.

Fife said these same party members are concerned that Turmel could be overshadowed by Liberal Leader Bob Rae, who is a proven performer in the House of Commons and a better-known personality with Canadians.

"They think this could be a gift for Bob Rae and that Canadians will see him as the official leader of the Opposition," Fife said.

While Layton intends to be back at the helm of the New Democrats when Parliament resumes in September, many suspect that the battle for his health could permanently force him from his job. And that could leave Turmel as the NDP leader well into the fall.

The 61-year-old Layton had faced health problems for some time before making his announcement on Monday. He fought a battle with prostate cancer that he appeared to be winning, though the NDP leader has said his current illness is a completely new cancer.

Layton's illness comes at a time when the New Democrats have enjoyed the greatest electoral success in their history.

The results of the May election left the NDP as the Opposition for the first time in their history, as they won dozens of seats in Quebec, largely at the expense of the Bloc Quebecois party.

With files from The Canadian Press