TORONTO -- The Working Families Coalition is launching an ad campaign to counter what it calls the "anti-worker agenda" of Progressive Conservative Leader Tim Hudak.

"There's no doubt that the paths to prosperity plan that Mr. Hudak has will have very negative impacts on all working families in the province of Ontario, and more specifically on women," Working Families spokesman Pat Dillon said.

"I don't think we have to create a Third World economy to create jobs."

Ontario will be getting a new premier over the weekend when Liberals gather to choose a replacement for Dalton McGuinty. The winner could choose to call an election within weeks or try and keep the minority legislature alive with the help of the NDP or PCs.

Launched by a group of unions that originally included teachers, nurses and the construction trades, Working Families has run TV ads in every provincial election since 2003, harshly attacking the PCs each time. The Tories have called them nothing but a front for the Liberals but lost a court challenge in 2012 aimed at silencing the group.

Published estimates of their ad buys run from $2 million to $9 million but Dillon, who also serves as the business manager for the Provincial Building and Construction Trades Council of Ontario, declined to say how much the latest round is costing or when it will launch.

"We're not taking a position on who we support and we're not taking a position on, as a political party, who we don't support," Dillon said.