NDP deputy leader Thomas Mulcair says the whole party is standing behind Jack Layton in his fight against cancer. 

Layton stepped down as party leader Monday to concentrate on his health, recommending the party's federal council choose Hull-Aylmer, Que., MP Nycole Turmel as interim leader.  

Mulcair said he supports that recommendation, pointing out he was there to help announce Turmel's candidacy. 

"Madame Turmel will receive my full support as interim leader. She's a great choice," he said, adding that he and Layton talked about the recommendation. 

"Jack and I had a chance to go over it. In the current context, it was by far the best choice." 

Mulcair and Libby Davies, who is the party's other deputy leader, will stay in their roles and help the interim leader.

New Democrat MPs are still getting over their shock at Layton's latest cancer bombshell, but are determined to support their leader as they pick his temporary replacement.

The news, as well as Layton's physical appearance, not only surprised Canadians, but his own caucus and staff.

Some of them only learned by watching Monday's press conference that their leader would be stepping away from his post temporarily to focus on fighting his second bout with cancer. They spent the rest of the day making and taking calls from each other and from friends, supporters and other colleagues.

"It came a bit as a surprise, I think, for many of us," Hélène Laverdière, the Quebec MP who defeated former Bloc Québécois leader Gilles Duceppe in last May's general election, said Tuesday morning. "We are deeply, deeply moved by what is happening to our leader and the new challenge he is facing."

Laverdière said the NDP caucus is rallying behind Layton, his strength and his courage.

Ottawa New Democrat MP Paul Dewar was out of town Monday and learned the news first by email, then turned on his radio and heard Layton's weak voice. "It shook me, very deeply," he told reporters Tuesday.

Dewar said Layton's hope and determination are inspiring and that if there's one person who can take on cancer and beat it, it's his leader. Layton is a good friend to his colleagues, said Dewar, and they are ready to do whatever he needs to support him, he said.

"What we need to do right now is all do our jobs even harder and work more than ever before to ensure that we're doing everything we can, which is making him proud of who we are as a party, as a caucus and helping Canadians," said Dewar.

Layton has seen an outpouring of support from current and former political friends and foes; from his constituents in Toronto; in Quebec, where the province's support for the NDP propelled it to Official Opposition status; and from Canadians across the country.

NDP caucus anxious to meet

Nova Scotia NDP MP Megan Leslie said the caucus is anxious to gather Wednesday in Ottawa for a meeting where members will discuss Layton's recommendation for an interim leader, Quebec MP Nycole Turmel.

"We're all really looking forward to seeing each other tomorrow at our caucus meeting because we're close, we're like a family, and we will get through this," Leslie said in an interview with CBC Radio.

She said this is an emotional time for the NDP, but that MPs won't let their leader's absence and personal struggle drag them down and affect their morale.

"I think this is going to be an incredible exercise for all of us. I think we will be stronger because of this, and we just will come together," Leslie said.

At the gathering, MPs will hear from Turmel, who is the NDP's caucus chair. Layton is expected to address his 103-member caucus via video link or telephone.

The NDP leader went public with his prostate cancer diagnosis in February 2010 and underwent treatment. Known for his dedication and passion for his job, he carried on as leader since that diagnosis. He only briefly took time off for surgery earlier this year to repair a broken hip, and he proved to have enough stamina to fight the spring election campaign while still on the mend.

'She's pretty neutral in that she is a new MP, but we all know the work that she's done and we all respect her.'—NDP MP Megan Leslie about Nycole Turmel

Layton did not say Monday what kind of cancer he is battling now or what kind of treatment he is receiving for it at Princess Margaret Hospital in Toronto.

Leslie said she expects Turmel to have the full support of the caucus and that she was a "smart choice" to recommend as interim leader.

"She's pretty neutral in that she is a new MP, but we all know the work that she's done and we all respect her work. I think it was a good decision on Jack's part," the Halifax MP said.

As a rookie MP, Turmel doesn't have the same name recognition as the NDP's two deputy leaders, Thomas Mulcair and Libby Davies, or other longer-serving MPs such as Paul Dewar, Pat Martin, Charlie Angus or Layton's wife, Olivia Chow. But she has a high profile in union circles because of her long involvement in organized labour, including a stint as president of the Public Service Alliance of Canada. She led the union, one of Canada's largest, from 2000 to 2006 and was the first woman to hold the position.

The Quebec MP, who represents the riding of Hull–Aylmer, also has a more than 20-year history with the NDP.

"There's strong support for her, and for good reason," said Dewar, calling Turmel a seasoned and professional leader who works well under pressure.

In an interview with CBC on Tuesday, Turmel said this is a "difficult period" for her party but that the NDP will carry on and is rallying behind Layton.

"We want to make sure that Mr. Layton is OK, that his health is his priority, and for us, we'll do what we have to do," she said.

Quebecers, constituents, Canadians show support

Quebec voters gave 59 seats to the NDP, up from one, in the spring election, and now Layton's temporary absence is raising questions about the party's future in the province.

Party faithful said news of his renewed fight with cancer is sad but that his absence won't harm the NDP's popularity in Quebec.

"The last numbers showed that the individual NDP members have actually surpassed Jack in popularity in Quebec," said New Democrat Tyrone Benskin, the MP for the Montreal riding of Jeanne–Le Ber. "I do not feel that this puts the party in jeopardy in the province."

Laverdière said Quebecers are reacting the same way as other Canadians, expressing their support and best wishes for Layton.

"The messages are flowing in," she said. "The surge of support from the population is quite striking."

Residents of Layton's riding of Toronto–Danforth were saddened by the news and expressed shock at how sick their MP sounded and looked Monday when he announced his diagnosis. One resident told CBC she was "destroyed" by the upsetting news.

Prime Minister Stephen Harper released a statement following Layton's news conference, as did interim Liberal leader Bob Rae and Green Party Leader Elizabeth May.

"We were all very saddened yesterday to hear the news of Mr. Layton's health," Harper told reporters in Ottawa. He said he spoke to Layton by phone on Monday. "I'm obviously, as we all are, encouraged by his courage, his hope and his determination to fight this."

Layton is aiming to be back on Parliament Hill when the fall session begins Sept.19, and the prime minister said he is hoping for the same thing.

"I hope to see him in the political arena opposite me in the not too distant future," Harper said.

Defence Minister Peter MacKay, speaking in Winnipeg Tuesday, called Layton a fighter and said he admires his perseverance.

"I've known Mr. Layton a number of years. His father served in Parliament with my father. And I can't help but sympathize with his family in what is clearly a traumatic and difficult time," MacKay said.

Rae, in Ottawa to sign a book of condolences at the Norwegian Embassy, said he was stunned to hear the news.

"I saw him just at the closing of the session. He looked a bit tired but nothing like what [was on] the news yesterday, so I was really very, very saddened to hear," he said.

Rae said he's a great believer in Layton's resilience.

"The guy went through an election campaign with a broken hip and scored a tremendous win for his party in terms of the increase in support. I don't want to speculate on any political outcomes. I just think the health outcome is the most important thing [and] I am really hoping very much that things work out."