OTTAWA -- Federal New Democratic Party Leader Jagmeet Singh emerged from his party's national convention with a strong mandate to overcome the many challenges ahead for the NDP to beat the Liberals at their own game and deliver in 2019.

The three-day convention, which wrapped up Sunday, was Singh's first since he was elected NDP leader in October, and a key opportunity for him to inject momentum into his party as it starts looking toward next year's election.

Memories of the NDP's disappointing showing in the 2015 campaign -- and the discord that plagued the party's last convention in 2016 -- were still fresh in the minds of many delegates. Meanwhile, the party remains stalled in the polls and failed to gain much ground in several recent byelections.

But following a rousing speech on Saturday, in which Singh railed against inequality by defending taxes and big government while taking aim at foreign web giants, the "ultra-rich" and the Trudeau government, the party was clearly behind him. More than 90 per cent of delegates voted against choosing a new leader.

New party president Mathieu Vick was frank about the challenges facing New Democrats, including the need to raise more money and mobilize the party's membership, which is in the midst of a major transformation from its union and socialist roots.

He believed the path that Singh began to chart at the convention was the right place to start.

"That's one of the lessons that we learned in 2015: That cautious change is maybe not the right message for the NDP. We do need bold, transformative changes," he said.

"And we saw that (Saturday): expanding public services; decriminalizing drugs; making sure that all of our infrastructure is public. Those are some of the things that we want to speak to Canadians about, and I believe that message will resonate."

One major issue for Singh and the party is how they'll differentiate themselves from the Liberals, who outflanked them on the left during the last election and have continued to appeal to progressive voters.

The NDP is also looking for ways to regain ground in Quebec, where the party made a huge breakthrough in 2011, lost ground to the Liberals in 2015, and could face a challenge selling a Sikh leader who wears a turban and kirpan in a province where voters support bans on public displays of religious symbols.

Singh began to put meat on his plans to deal with some of those challenges.

First, by calling for more government services such as universal pharmacare, and then by indicating his support for any effort to re-open the Constitution to include Quebec and First Nations.

In a French interview with The Canadian Press, Singh said he didn't know what the exact process is to re-open the Constitution.

"But the idea is clear that all nations, all provinces must be signatories of the Constitution. I recognize that this is a problem and it needs to be fixed," he said.

Delegates backed much of Singh's vision in various resolutions, which included free tuition, promising to introduce proportional representation voting, and closing various tax exceptions.

Yet some publicly complained that resolutions supported by multiple riding associations were buried because of potential divisiveness.

They included a call for the NDP to formally oppose the Trans Mountain Pipeline; to boycott Israeli goods made in the West Bank; and to adopt the Leap Manifesto, which calls for a radical overhaul of Canada's economic system.

None of those issues were mentioned by Singh, who also made only a passing reference to the environment in his speech.

"We had a well-worded resolution on justice for Palestine that had 37 riding associations supporting it that was buried," said NDP MP, and former Singh rival, Niki Ashton.

"That was very frustrating for a lot of our activists and for me, and I think what we've seen over the weekend is that people aren't willing to put up with that way of doing things. That members want to be heard and want to have a say in what issues have priority."

In separate interview with The Canadian Press, Singh sidestepped questions about whether the NDP should set a more realistic target of beating the Liberals in 2023. He also refused to say whether he would quit as leader in 2019 if the party fell short of expectations.

"If there's a point where I'm no longer able to make life better for people or to advance those issues, then that's the point where I'll say: 'Well, let's re-evaluate."

-- With files from Mylene Crete.