The NDP isn't Prime Minister Justin Trudeau's only option for getting legislation passed in the next session of Parliament, but party leader Jagmeet Singh is arguing the Liberals need the support of a progressive and "national" caucus.

Looking for common ground ahead of the House returning next month, Trudeau and Singh met in Ottawa this morning behind closed doors.

Although the Liberals have the option of working with Bloc Québécois Leader Yves-François Blanchet, whose party surged to third place in the House of Commons, Singh said Trudeau needs the NDP's support because it's the only progressive "national" party.

"Mr. Blanchet has made it really clear that he's not interested in working on national programs that benefit all Canadians. That's not his goal, that's not his party's goal, and frankly that's not his job. He was elected in Quebec, for Quebecers, and that's fine," said Singh, who now heads the fourth-place party in the Commons.

"If Mr. Trudeau wants to pass ... something that's national and progressive that benefits all Canadians, he's got really just two choices. He can work with us or the Conservatives."

Just 24 hours earlier, Blanchet met with Trudeau and doubled down on his separatist views.

"I still believe that Quebec will do better when it becomes a country," he said on Wednesday. "So I'm not the one that will fight to have a nice, beautiful and united Canada."

Push for pharmacare

Singh has been trying to leverage his 24 seats to generate momentum for his party's policy objectives. He already has threatened to vote against the upcoming throne speech if it doesn't mention some of his party's key policy priorities, such as introducing a national, universal pharmacare program.

"I know that in this Parliament they're going to need to work with us. I know that they're going to have opportunities that they're going to need New Democrats to vote for a bill," he said.

"I want to make it clear that isn't going to come for free."

Watch: Jagmeet Singh says he is willing to work with the Liberals with 'clear commitments'

After meeting with Prime Minister Justin Trudeau this morning, NDP Leader Jagmeet Singh says he's open to working with the Liberals, but his support will come at a cost. 0:42

Singh left a letter with Trudeau which lists the policies and projects he'd like to see on the government's agenda.

"It is our expectation – and that of Canadians – that the upcoming throne speech will include a clear timetable that lays out a path to implementing universal, comprehensive, public pharmacare without delay," it reads.

"We will bring forward a framework for a national pharmacare program, and welcome the opportunity to work with you to expedite progress on legislation, funding, and implementation in 2020. Calling a Health Ministers meeting in January would be a good first step to begin the talks for national pharmacare."

NDP 'ready' for a campaign if necessary

Parliament is set to return Dec. 5. Returning MPs will elect a House Speaker and the Governor General will then deliver the speech from the throne outlining the government's priorities for the session.

If the speech goes to a vote, it would be the new House of Commons' first test of its confidence in the minority Trudeau government.

Losing a vote on the throne speech could trigger another election, or give the opposition Conservatives an opportunity to ask the Governor General for a shot at forming a government. A vote is not mandatory, however, and other governments have skipped it.

When asked if his party — which has struggled with fundraising in recent years — is ready for another campaign, Singh said, "I'm ready. I'm ready any time."

Singh's letter to Trudeau also says he'd like to see the Liberal government adopt the New Democrats' campaign promise to provide full public dental coverage to households making less than $70,000 a year.

Watch: Blanchet still believes Quebec will do better as its own country

Bloc Québécois Leader Yves-François Blanchet says that he is not the best person to advise western Premiers about separation because he is not in favour of them trying to create an oil state in western Canada. 0:56

"New Democrats will work in this Parliament to deliver dental coverage for those who need it and we will be looking for indications in the throne speech that you share this priority," it said.

The NDP leader also urged Trudeau to drop a federal appeal of a human rights tribunal ruling that ordered the government to compensate Indigenous children and families hurt by the child welfare system.

Before their closed-door meeting began, Trudeau said he and Singh share a number of policy priorities, including tackling climate change, addressing affordability issues, working on reconciliation with Indigenous communities and pursuing a pharmacare plan.

Trudeau has been meeting with the opposition leaders prior to the new session of Parliament. He met with Conservative Leader Andrew Scheer and Blanchet earlier in the week and will meet with Elizabeth May of the Green Party on Friday.