OTTAWA — Conservative Leader Andrew Scheer is signalling that he’ll look to form government if his party wins the most seats, but not a majority on election night, setting up a potential challenge of long-standing parliamentary tradition.

While there is no rule book, convention and history has established that the incumbent gets the first chance to attempt to continue to govern and test the confidence in the House of Commons in a minority scenario where seat counts are close and the outgoing prime minister has not conceded.

In an interview with CTV News Chief Anchor and Senior Editor Lisa LaFlamme, Scheer said, "We're not going to ask other parties for support. We're going to put our platform out to Canadians about how we're going to lower taxes, make life more affordable. And we will implement that agenda. We expect that other parties will respect the fact that whichever party wins the most seats gets to form the government and that they will understand that if Canadians -- when Canadians -- endorse our platform, that we would have the right to implement it."

Based on current polling, a majority government may not be in the forecast for either the Liberal or Conservative parties, with Scheer and Liberal Leader Justin Trudeau locked in a tie for first with neither party projected to secure the 170 seats needed for a majority.

If neither the Liberals or Conservatives win a majority it is possible that Trudeau would not resign or concede, and look to form a minority or coalition government with the smaller parties.

That means Trudeau could take the first chance to test the confidence of the House of Commons even if the Conservatives win more seats than the Liberals, a scenario it now seems Scheer is hinting he would challenge.

If Trudeau was to accept a Conservative victory on election night, that would signal the Governor General should invite the Conservatives to attempt to form government.

Faced with questions about potential minority scenarios on the campaign trail, Scheer has flatly rejected the notion of forming a coalition government, or working with any other party under any circumstance, calling the prospect of the progressive parties teaming up something "Canadians can't afford."

In his interview with LaFlamme, Scheer also restated that he would not seek the support of other parties, including the Bloc Québécois.

Scheer doubles down

“Our message would be that the party that wins the most seats has a mandate to implement what they put before Canadians. They have a mandate to form a government,” Scheer said during a follow-up interview with CTV’s Your Morning on Thursday.

When pressed on how he plans to implement the policies laid out in his “100 Day Action Plan” without the other parties’ support should he form a minority government, Scheer repeated that he’s confident that won’t be the case and his party will win a majority.

“Honestly, when it comes to the what ifs and the different scenarios, Canadians will decide what kind of parliament we’ll have on Oct. 21. We’re asking Canadians for a strong majority so that we can avoid a Liberal-NDP coalition,” he said. “I’m confident that we’re going to earn the support of Canadians.”

Scheer was also asked if he would step down as leader of the party if he fails to win a majority on Monday.

“We’re going to win on Monday,” he replied. “We’re very optimistic, very confident we’re going to win seats. We’re going to surprise a lot of people. When the analysts and the pundits see the results coming in, they’re going to see that we ran a very successful campaign and we will form the government on Monday.”

And, at a campaign event in Brampton, Scheer— who for years sat as the Speaker of the House of Commons and is well aware of the parliamentary conventions— emphasized that “in modern Canadian history” the party with the most seats, regardless of a majority or minority, forms government.

While that has happened, in the most recent example of 2006 where Liberal incumbent Paul Martin resigned in the face of a Conservative minority, his party had lost 32 seats whereas the Conservatives had gained 25 seats from their 2004 election standing. The standings heading into the 39th Parliament after the 2006 election were: Conservatives 124, Liberals 103, Bloc Quebecois 51, NDP 29, and one Independent.

Trudeau, Singh respond

Trudeau has so far dodged questions on whether he’d look at teaming up with any party post-election, saying he is focused on electing a progressive government with a “strong mandate” as the best way to stop the Conservatives.

Trudeau side-stepped the question again Thursday, saying a progressive opposition wouldn’t work for Canadians, or be able to protect them from Tory cuts.

Trudeau stated that “we are going to elect a government with Liberal MPs from right across the country who will continue the hard work of investing in Canadians of building a better future, of focusing on the fight against climate change.”

On Thursday, NDP Leader Jagmeet Singh, who’s been open to the possibility of forming a coalition government with more progressive opponents, like the Liberals, didn't respond directly to Scheer's comments but instead reiterated that his party would not support the Conservatives in a minority government scenario.

"We don’t respect Conservatives," said Singh. "Just because Scheer thinks that if he gets a certain number of seats, we’re going to give up fighting against Conservatives, no. We’re going to always fight Conservatives."

Though he also criticized Trudeau for putting Canadians in this position, saying that had electoral reform happened and the federal first-past-the-post system was no longer, then the electorate wouldn’t be facing another scenario where less than half of voters can choose a party and they still get “all the power.”

“It's wrong for the Conservatives to think that with less than 40 per of the power -- or vote -- they deserve all the majority of power. That's wrong," Singh said.

Bloc Quebecois Leader Yves-Francois Blanchet, too, was asked about the prospect of a coalition government during a campaign stop in Montreal Thursday morning. In response, he stressed that he has no interest in joining any kind of coalition.

The Bloc leader said he would work with the other parties on a case-by-case basis and review every proposal with respect to their potential benefit to Quebec. He said he is only looking out for Quebecers' best interests and that will guide him in approach to working with the other parties in passing legislation.

With files from CTV's Sarah Turnbull and Jackie Dunham