NDP Leader Tom Mulcair has received the unanimous support of his party's caucus after discussions about whether it was appropriate for him to continue his stewardship of the party.

Mulcair emerged from the caucus meeting with NDP national caucus chair Charlie Angus and the rest of the party's MPs.

"We are a united, unified caucus," Angus said. "That was the question that was put to us when we came in, are you united? Well, I can't speak before I meet all my colleagues, but I can speak today. Are we all united?"

The caucus cheered "yes" behind him.

Angus said Mulcair will remain leader of the NDP until his permanent replacement is chosen.

NDP Caucus Chair Charlie Angus says caucus is united 0:29

The party membership rejected Mulcair's leadership at a convention in Edmonton in April, voting 52 per cent to 48 in favour of a review.

Participants inside the room told CBC News that caucus members raised concerns about Mulcair's low profile this summer and that the party had lost focus. They said once the caucus agreed to keep him on as caretaker leader, Mulcair told them he was "humbled" and pledged to take a more consensus-driven approach to leading the party.

"The caucus has asked us to take a very structured and tough approach with a government that's very good when it comes to form, but not very long on substance," Mulcair told reporters after the caucus meeting.

"We've got a very clear vision of what would make Canada a fairer place whether it's in terms of the environment, on economic issues, social issues."

'Core values'

The NDP has struggled with slumping poll numbers and flagging fundraising since the Liberal government was elected by many of the same left-leaning voters who were considering casting their ballots for the NDP just a year ago.

Mulcair attempted to address the party's questions about its identity as the retreat began Wednesday morning.

"Those are our core values: environmentalism, pacifism, feminism, socialism," Mulcair said to applause from the room.

The caucus retreat is also looking at how the NDP can face off against Justin Trudeau's Liberals as they enjoy an extended political honeymoon. That includes sessions on communications and social media strategy.

"Going beyond the imagery, going beyond the press conference, talking to Canadians about what's actually happening," Mulcair said of the task facing his caucus.

Tom Mulcair kicks off the NDP caucus meetings by saying that his only adversaries in politics are the Liberals sitting across from him in the House of Commons. 0:51

He said the Liberals have failed to deliver on several items, including reforming the National Energy Board ahead of the Energy East pipeline hearings, increasing funding for health care and making changes to C-51, the anti-terrorism law.

The sale of armoured cars to Saudi Arabia also came up as a major issue during Mulcair's speech.

"Selling arms made in Canada to one of the most repressive regimes, when we know that similar arms have already been used by that country to go against civilians, that's shameful," Mulcair said. "That's why we fight."

Angus introduced Mulcair before his caucus speech, offering a preview of some of the framing the NDP may use as Parliament resumes next week.

"You know, Mr. Trudeau, he borrowed our platform," Angus said. "We have a real opportunity to make him deliver the goods now."

Leadership question 'in the air'

Several MPs ducked questions before the caucus meeting about whether they support Mulcair staying on as leader in the House of Commons.

During a morning coffee break, Montreal MP Alexandre Boulerice, who recently announced he wouldn't pursue the permanent leadership of the party, said the question was hanging over the meeting.

"It's in the air. We'll discuss it, but I have confidence in the leadership of Mr. Mulcair," Boulerice said. "No problem."

Abitibi-Témiscamingue MP Christine Moore said Mulcair's performance in the House of Commons will be important again this fall.

"I think to keep Mr. Mulcair is really the best solution for us," Moore said.

"We will probably have this discussion, but I don't think we have to stay too long on that …. Maybe we need to re-explain why it's important to keep Mr. Mulcair."