The leader of Canada’s left-of-centre New Democratic party is facing a key byelection on Monday which will decide whether or not he is able to challenge Justin Trudeau in October.

Jagmeet Singh, the first non-white leader of a major political party in the country’s history, must win the byelection in Burnaby, a city east of Vancouver, in order to get a seat in parliament and be in position to go up against the PM in this year’s general election.

While parties often decline to challenge a leader seeking a seat, both the Liberals, Conservatives and the newly formed People’s party are running candidates in Burnaby South.

Singh, the former human rights lawyer-turned-politician surprised his party – and the country – when he wrapped up the leadership race with a decisive first ballot win more than a year and a half ago. His quick rise in federal politics has excited voters across the country.

“His leadership can be seen as refreshing. People saw him as this very telegenic, easy-to-like guy, who might be able to compete on the celebrity level with Trudeau,” said Lori Turnbull, the director of Dalhousie University’s school of public administration.

But since his leadership win in late 2017, he and his progressive party have fallen into disarray. Sitting parliamentarians have resigned; others have indicated they won’t seek re-election. To make matters worse, the plurality of the seats currently held by the NDP are in Quebec, a province where support for the party has plummeted.

“He’s going to get wiped out completely in Quebec,” said Nelson Wiseman, a political science professor at the University of Toronto. The current situation is a far cry from the the party’s “orange wave” success in Quebec under former leader Jack Layton. Even as recently as the summer of 2015, multiple polls had the NDP on the verge of winning their first federal election, only to have their dreams dashed by a late surge by Justin Trudeau’s Liberal party. The NDP currently sit a distant third in national polling.

With party veterans fleeing, haemorrhaging finances and weak poll numbers, the rookie leader has the daunting task of salvaging and reconstituting the left-of-centre party, ensuring a battle-ready machine for the country’s election later this year.

Some of Singh’s challenges can be attributed to his absence in the House of Commons: despite leading the party, he remains seatless.

“Because he doesn’t have a seat, he hasn’t really been given a lot of opportunity to indicate what his message is. He’s not in the house with the rest of the [leaders],” said Turnbull. While touring across the country seems like a good idea, she said, Singh can’t be seen trading barbs with other party leaders.

Some feel that Singh’s status as the first non-white leader of a major political party has also prompted unfair criticism of his tenure. While newly minted political leaders in Canada get “put through the wringer”, the treatment of Singh has been disgraceful, said Rick Smith, executive director at the progressive Broadbent Institute and a former NDP staffer.

“What doesn’t get nearly the amount of focus that it deserves in the media is the daily a torrent of racist nonsense that gets thrown his way,” he said.

At the same time, the problems gripping the party are not Singh’s alone.

“The NDP has always had a bit of an existential crisis, maybe even more than other parties. At some point, a party has to decide, is it their goal to win an election?” said Turnbull. “Or is to set out principles and be true to those principles, even if sometimes they’re not politically popular?”

The broader weakness of the party also raises questions about the future ambitions of the party in Canada’s left-of-centre politics. Long seen as the “conscience” of the country’s political system, the party increasingly has to compete against the Liberals to its right – and the Green party to its left.

But Smith isn’t convinced the party’s prospects are dire.

“Over my adult life, the NDP has grown much stronger everywhere across the country,” he said, calling it a “much more sophisticated political machine” than it was even a decade ago.

He sees Singh as a deeply capable, charismatic leader – pointing to his ability to drive high turnout in key races – and his ability to flip regions, like the Toronto suburbs, to the NDP. For Smith, there is little to fret over in the upcoming byelection: “He was always going to win in Burnaby … This is a guy who is very warm, likeable, engaging and knowledgeable.”

Monday’s test will be politically existential for Singh: as he canvasses neighbourhoods, party members have said Singh’s continued leadership is unlikely if he fails to win.