If the Conservatives win a minority government on Oct. 19, Stephen Harper's main political rivals say they will work together to defeat the Conservatives.

While NDP Leader Tom Mulcair and Liberal Leader Justin Trudeau each say they are focused on winning enough seats to beat the Conservatives and form their own government, questions persist about what might happen in this minority scenario after October 19.

While the Liberals have said no to a formal coalition with the NDP, both parties are willing to agree to prop each other up if the Conservatives win a minority.

NDP Leader Tom Mulcair told CTV's Question Period that he has had enough of Harper and will not, under any circumstance, support him.

"If he's willing to play that type of divisive politics based on race and religion, I don't want anything to do with him. I don't think he deserves to be the Canadian prime minister. I want to beat and replace him and start repairing the damage that he's done," Mulcair said on Sunday.

Liberal Leader Justin Trudeau also said he would not support a possible Conservative minority government.

"I am confident that Canadians on October 19th are going to make a better choice. We're working hard to offer that. But, no, I will not be supporting Mr. Harper as prime minister," said Trudeau.

Liberal Communications Director Kate Purchase confirmed the party's willingness to informally work with other parties in the House of Commons.

"We've always said that we'll work with any party in the House to pass good legislation but we're not entering any formal agreements with other parties," said Purchase.

But the Trans-Pacific Partnership (TPP) might wedge itself between the NDP and Liberals.

The NDP opposes the new trade deal between the 12 TPP partner countries, expressing concern about the implications for the Canadian auto and dairy sectors. The Liberals, on the other hand, have said that they will have to look at the details of the agreement, but stressed that they are a "pro-trade party."

Speaking on CTV's Question Period, Mulcair was unclear whether the NDP's hypothetical support for the Liberals would be contingent on opposing the massive trade deal.

"We would never put that deal before Parliament. We would try to get a better deal, the same way (U.S. Democratic presidential candidate) Hillary Clinton says that doesn't like the deal that's been negotiated for American working families, I don't like the deal that's been negotiated," Mulcair said.

Mulcair accused the Conservatives of going to the last round of TPP talks in Atlanta unwilling to negotiate a good deal.

"You come to a poker table, you're holding a pair of deuces and you're going to try to bluff your way to what? Mr. Harper had two weeks left in the campaign. Everybody around that table knew they could play him for a chump."

Mulcair holding out hope

Mulcair said he is is still hopeful that the NDP can bounce back after a drop to third place in the polls last week. He acknowledged that his support of a Federal Court of Appeal decision allowing women to wear a niqab at citizenship ceremonies hurt him in Quebec, but stood by his position. He accused Harper of playing "race politics" in his attempt to politicize the court decision.

"This is Mr. Harper again using race, using religion, using people's personal background and ethnicity, as a wedge in a political campaign. I find that beneath contempt from a sitting prime minister. I've never seen that my life."

He also said he is confident that a number of blue seats in southern Ontario, where the auto sector has taken a hard hit, will turn orange on Oct. 19.

"Of the 400,000 jobs lost in manufacturing under Stephen Harper, 260,000 of them were lost in Ontario. In those ridings, people see hope with the NDP and know that we're going to fight the Trans-Pacific Partnership. We're the only ones who will."

The NDP leader is also asking Canadians to consider the numbers when they cast their ballots, if they're hoping to oust Harper.

"The NDP is already starting from a base of 100 seats. We need 35 more seats to defeat Stephen Harper. The Liberals have 30 some odd seats. They need 100 seats," said Mulcair. "The party that can defeat and replace Stephen Harper is the NDP."