Veteran Liberal MP Denis Coderre says he favours merging his party with the New Democrats.
But the Montreal MP seems to be a lone voice at a four-day Liberal caucus retreat to plot strategy for next month's resumption of Parliament.
Interim Leader Bob Rae and other current and former MPs say a merger is not in the cards, even though both opposition parties are weakened and leaderless.
Jack Layton's death last week has left the NDP reeling and has revived speculation about a possible merger.
Mr. Coderre says the outpouring of grief for Mr. Layton signalled to him that Canadians want a united, progressive alternative to Stephen Harper's Conservatives.
But Mr. Rae says uniting with the NDP is not on the agenda.
He says Liberals – reduced to a third-party rump of only 34 seats in the May 2 election – need to focus on getting their own house in order.
"That's not on our agenda," Mr. Rae told reporters Monday on his way into a Liberal caucus retreat to plot strategy for the Sept. 19 resumption of Parliament.
"People are free to talk about whatever they want to talk about, but it's not on my agenda at the moment. I think we really have to focus on the Liberal party."
Mr. Rae, who spent the summer meeting with Liberals across the country, said "resilience" was the best word to describe the mood of party members.
"My sense of the Liberal Party is there's a tremendous spirit of resilience, there's a tremendous spirit of wanting to come back, of feeling that we are a force."
Other former and current MPs attending the four-day caucus retreat also ruled out a merger with the NDP, insisting the Liberals can make a comeback.
"I remain firmly convinced that our future remains as a Liberal party. There is no need to merge with anybody else," said Mark Holland, who was defeated in May.
Former MP Omar Alghabra said the party will bounce back if Liberals "get back to basics and if we focus on what Canadians care about."
"No shortcuts," he added.
Mr. Rae said it's not worth speculating about the impact Mr. Layton's death may have on the federal political landscape.
But with the largely rookie NDP caucus preoccupied with choosing Layton's successor, Liberals believe the veteran Mr. Rae and his more experienced caucus will have a chance to shine during the fall parliamentary session.
"I feel very confident in [Rae's] abilities and in his abilities in the House and I have a great deal of confidence in him carrying our message over the next while," Mr. Holland said.
However, deputy leader Ralph Goodale said Liberals "shouldn't be preoccupied by what some other party is doing."
"I think if we try to juxtapose ourselves with somebody else's problem or position, we really miss the point. We've got to do our homework and that's job No. 1."
In Parliament, Mr. Rae said that means being "an effective opposition" focused on the issues that matter most to Canadians: the volatile state of the economy and health care.
"The economy is not as strong as Mr. [Finance Minister Jim] Flaherty said it was going to be in June. We have a lot of uncertainties, both in the United States and in Europe, a lot of signs that the Canadian economy is slowing down and a lot of concern about that. So I think that's where we need to be focusing our time and effort."
Internally, he said it means developing the tools to build the Liberal membership and to more effectively raise money and communicate the party's message.