The Liberals today accused the Conservatives of using campaign tactics borrowed from the American far right — while Andrew Scheer called Justin Trudeau's actions on a potential school strike in Ontario "quite disgusting" — in the hours before the leaders assembled for the first English language debate.

Steve MacKinnon, the Liberal candidate for the Quebec riding of Gatineau, held a news conference in Ottawa to outline a number of what he called "highly deceptive" claims the Conservatives have made about Liberal policies. He also said the Conservatives were planning to launch a website falsely stating the Liberals plan to impose a new 50 per cent tax on home sales.

That website went live shortly after MacKinnon's news conference.

"Andrew Scheer and the Conservatives are borrowing tactics from the American far right and from Rebel Media by spreading misinformation on a vast scale," MacKinnon said.

The candidate said the Conservatives have spread several spurious claims about the Liberals, citing the suggestion a notorious British child killer was being allowed to come to Canada and their warnings about the negative impacts of the Liberal carbon tax.

The "hidden home tax" is another "major lie" the Conservatives are peddling, he said.

"These Conservatives have been making up alternative facts for the entirety of this campaign and before," MacKinnon said. "And that behaviour is behaviour that Canadians are fed up with and it's behaviour that we're going to continue calling out."

The document shared by the Conservatives on the home tax website is edited from the original 45-page source document, a copy of which was obtained by CBC News earlier this summer. The Conservative material takes a short excerpt from a list titled "Ontario caucus priorities" for the party's 2019 platform.

In the original document, several Ontario MPs listed both proposals and ideas to be considered ahead of the fall federal election.

Responding to the Conservative website accusing the Liberals of harbouring a secret plan to tax home sales, the Liberal war room said the material posted by the Conservatives represents a single proposal among many in a summary of independent testimony from a range of people.

The Liberals say the suggestion was never considered as a party proposal and that the Conservatives are "deliberately and knowingly spreading misinformation."

On Twitter, Liberal candidate Adam Vaughan said the idea was floated at town halls by members of the public. He flatly denied the party ever planned to adopt the idea.

"It was never discussed as a policy. It's not a position I support. It's not Liberal policy. It's as real as Scheer's claim to be an insurance agent," he tweeted.

To be clear: We will NOT put a 50% tax on the sale of your home. <a href="https://t.co/EyXcgO9VFV">pic.twitter.com/EyXcgO9VFV</a> —@JustinTrudeau

The accusation came just hours before Scheer and Trudeau were set to share the stage for the English leaders' debate.

Daniel Béland, a political scientist at Montreal's McGill University, said this campaign has turned "particularly negative."

"The two main party leaders are not so attractive this time around, so a major aspect of their discourse is about why the other guy is such a bad choice," he said.

Earlier today, Scheer lashed out at Trudeau, accusing him of using the threat of a teachers' strike in Ontario to score political points. Trudeau repeatedly has pointed to cost-cutting actions by the government of Progressive Conservative Premier Doug Ford and has suggested Scheer would make similar service cuts that would harm Canadians.

Scheer: Trudeau's actions 'quite disgusting'

"I think if there's one parent who's disappointed in the strike action being resolved today, it's Justin Trudeau, and it's quite disgusting that he was trying to politicize kids' education for his own personal partisan gain," he said.

About 55,000 education workers in Ontario were poised to strike Monday. The job action was called off after the province reached a deal with the Canadian Union of Public Employees.

Even though education is a provincial responsibility, federal Conservatives were worried about the potential impact of a strike on their political fortunes in Ontario — particularly in crucial swing ridings in the Greater Toronto Area — because they have heard repeatedly from voters that Ford's record makes them reluctant to vote for Scheer.

Six party leaders will take part in one English and one French debate hosted by the Canadian Debate Production Partnership. Left to right: Justin Trudeau (Liberal), Andrew Scheer (Conservative), Jagmeet Singh (NDP), Elizabeth May (Green Party), Maxime Bernier (People's Party of Canada) and Yves-François Blanchet (Bloc Québécois). (CBC)

The Conservative website hiddenhometax.ca says the Liberals have a "secret plan to implement a tax on up to 50 per cent of the profits on the sale of your home."

"Brace yourselves Canada: Justin Trudeau is coming for your wallet, only after the election, when he doesn't need your vote, but still needs your money," the website reads.

"You just can't trust Justin Trudeau. He is not as advertised."