The three-party jam in the race to form the federal government appears to have broken open, with the Liberals and Conservatives fighting for the lead as softening support for the New Democrats in Quebec is leaving them further behind the front-runners nationally.

The most recent results of a three-day rolling poll of 1,200 randomly selected Canadians conducted by Nanos Research for The Globe and Mail and CTV suggest that the Conservatives have the support of 32.8 per cent of voters while the Liberals have the support of 31.7 per cent.

Given that the survey results are expected to reflect the opinions of the broader Canadian public within 2.8 percentage points 19 times out of 20, the numbers suggest that the two parties are virtually tied.

But Thomas Mulcair’s New Democrats, who were ahead of their rivals in early September and locked in a statistical tie with them throughout most of the month, had the support of just 26.1 per cent of respondents after the most recent evening of polling on Wednesday.

Those numbers suggest that, at this point in the long election campaign, Justin Trudeau’s Liberals are capturing the interest of more centre- and left-leaning voters, creating a problem for the NDP as the Canadians whose primary aim is to topple Stephen Harper and the Conservatives choose their champion.

“For the New Democrats, the trend line has been working against them over the last six to seven days of tracking,” Nik Nanos, president of the polling company, said in a telephone interview.

The numbers started to slide for the New Democrats after they released the costing of their platform last week and they continued to slide after the French-language leaders debate that was held last Thursday.

The NDP numbers in Quebec, where the party has been well ahead of the other contenders since the 2011 election, suggest an uneven but pronounced decline over the past three weeks as the Conservatives gained some steam in that province – though the poll’s margin of error for Quebec alone is significantly higher than the cross-country numbers.

During the French debate, Mr. Mulcair defended a woman’s right to wear a niqab to cover her face during a citizenship ceremony – something that is broadly opposed by Quebeckers.

With less than three weeks before the Oct. 19 vote, support for the parties is starting to solidify. Fewer respondents say they are undecided. And the Liberals appear to have some momentum.

“For a lot of voters, they are faced with a series of imperfect choices,” Mr. Nanos said. “So perhaps one frame would be, ‘Who is the least imperfect challenger to Stephen Harper?’ ”

He said the NDP is “not out of the race by any stretch. But they have to get back in the pack.”