Four NDP MPs have come out in support of Thomas Mulcair in a leadership bid he hasn't actually declared yet.

At a two-day meeting with little news and few policy announcements, leadership quickly became the subject most people focused on.

The NDP's leadership nomination process officially began on Thursday.

Only Brian Topp, who is stepping down from his position as the party's president, has said he will run for the leadership.

On Thursday, Manitoba MP Niki Ashton added her name to the lengthy list of caucus members who are testing the leadership waters, including Nathan Cullen, Libby Davies, Paul Dewar, Peter Julian, Thomas Mulcair and Peggy Nash.

Pat Martin has also said he'll run if no other candidate is open to working with the Liberal Party, though he emphasized he's staying away from the word merger.

The NDP caucus was in Quebec City for planning and strategy meetings as they prepare to head back to the House of Commons next Monday.

Heading into Thursday's morning session, Quebec MPs Robert Aubin, Jamie Nicholls and François Lapointe stopped to say they support Mulcair for leader and hope he'll declare his candidacy.

"I'd like to encourage him to come out and declare because I think that there's a groundswell of support for him," Nicholls said.

Asked what constitutes a groundswell, Nicholls said he has "talked to a few people and they're ready to support Tom."

He said Mulcair did not ask him to declare his support.

Coming out of the morning meeting, Quebec MP Claude Patry also said he'll vote for Mulcair. Patry is a former union leader, potentially an important supporter for Mulcair, who leans to the right among NDP MPs.

Mulcair said Tuesday he wouldn't make an official announcement about his candidacy until he had lined up his campaign team.

"We're weighing all our options, we're looking at the types of people who can help us, we're getting a lot of support and encouragement across Canada. And when and if we do announce, it'll be with a full team capable of taking up the challenge of leading the Official Opposition," he said Wednesday.

Mulcair's declared supporters so far, however, are much lower profile than Topp's biggest booster, former NDP leader Ed Broadbent.

B.C. MP Peter Julian, who also is considering a leadership bid, picked up his first two endorsements Thursday.

"I think he'd make an excellent candidate," said Windsor, Ont., MP Brian Masse. "I think it's healthy to have a number of people in there."

Toronto MP Rathika Sitsabaiesan said she believes Julian would make "a good prime minister." She said the bilingual MP is personable, "brilliant and very articulate" and would be able to connect with folks at both the boardroom table and the kitchen table.

Turmel announced Wednesday rules requiring those with parliamentary or caucus functions to step down, although she left the deputy leader off the list of positions whose holders would have to give up their files during the race. That means high-profile critics, like foreign affairs critic Paul Dewar or finance critic Peggy Nash, would have to relinquish their titles while deputy leaders Mulcair and Davies could hang onto theirs.

At least two caucus members said they thought the deputy leaders were covered by that rule, leading to confusion as MPs left their morning meeting.

MPs, however, emphasized unity throughout interviews Tuesday and Wednesday, with officials saying they intend to focus on applying pressure to Prime Minister Stephen Harper's government over the economy, and on outreach to hang onto supporters and win new ones.