OTTAWA -- The Toronto Raptors and the Golden State Warriors aren't the only ones who'll be trying to score during Game 5 of the NBA finals.

The Conservative party will be competing with a third party advocacy group, Engage Canada, in a bid to define Tory Leader Andrew Scheer ahead of this fall's federal election.

The Conservatives have been running television ads throughout the basketball playoffs, introducing Scheer to viewers as a regular guy from a middle class family who'll repeal the carbon tax and otherwise help make life more affordable for average folks.

But on Monday, Engage Canada will join the fray with two 30-second spots painting an entirely different picture of Scheer: as a "yes man" to Ontario Premier Doug Ford.

Engage bills itself as a non-partisan third party, founded by former Liberal and NDP strategists and made up of individuals, labour organizations and professional associations who share the common goal of ensuring Scheer never becomes prime minister. The group was similarly active against former Conservative prime minister Stephen Harper in the run-up to the 2015 campaign.

Engage spokeswoman Tabitha Bernard refuses to say how much money the group has devoted to the Game 5 ad campaign, other than to say "our buy is substantial."

"We're pretty excited to be able to be competitive. This is sort of a David and Goliath operation," Bernard said in an interview.

Ads that run during the NBA finals would be among the most expensive available, reaching an audience of some 10 million or more Canadians who have rallied behind the Raptors as "Canada's team."

Bernard confirmed that Unifor, Canada's largest media union, is involved in Engage but refused to quantify its role. Unifor president Jerry Dias, whose union also represents auto workers among others, has vowed to be Scheer's "worst nightmare."

The Conservatives have been denouncing the Liberals' intention to include Dias in an expert panel that is to advise the government on the make-up of an independent body that will decide how to divvy up almost $600 million over the next five years in tax credits and other incentives for struggling news outlets.

By running ads now, Engage does not have to reveal where its money is coming from or face any limit on its spending.

Under new rules imposed by the Trudeau government, all third parties will face spending limits and must disclose donations as of June 30, the start of what's called the "pre-writ period" before the official start of the election campaign. Bernard said Engage has plans for ads up to the end of June and will "see what happens" after that.

In late May, Engage unveiled its first TV ad, which portrayed Scheer as a bobblehead who says yes to tax cuts for wealthy individuals and big corporations and to Ford-style cuts to health care. The group has also been running "lapdog" radio ads. All the ads, including the new one to air during Game 5, end with the tag line: "Andrew Scheer. His weakness will cost you."

The new ad combines a shortened version of the bobblehead ad with a new segment featuring a photo-shopped picture of a seated Scheer with a menacing-looking Ford standing behind him while a narrator warns that Scheer won't stand up to Ford's cuts to health care and education and will make similar cuts at the federal level.

While the ad will have broad reach across the country, Bernard said the ad is aimed particularly at voters in urban and suburban centres in Ontario, where Ford's popularity has plunged since winning power just a year ago.