A group representing Ontario businesses warned the Liberal government Monday against making major changes to labour laws that could have a negative impact on the province's economic recovery and lead to job cuts.

In a letter to Premier Kathleen Wynne, the Ontario Chamber of Commerce expressed its concerns about the province's Changing Workplaces review, a top-to-bottom look at labour laws that is expected to usher in major changes.

"There is a sense amongst the employer community that politicians are either unaware or significantly underestimating the cumulative financial burden of recent policies that have increased the cost of doing business in the province," the business group wrote in the letter.

"Employers stress that the resulting cost escalation would act as a direct constraint on their ability to invest in the human and physical capital required to ensure the future prosperity of the province."

Chamber of commerce vice-president Karl Baldauf said employers are especially concerned about potential changes to unionization. He warned that allowing unions in more sectors of the economy to use a card-based certification process to let employees form a union -- when enough workers sign a union card, without holding a vote on the matter -- could see workers unionized against their wishes.

The Ontario Federation of Labour, however, wants to see card-based certification extended to all sectors to make it easier for workers to unionize.

President Chris Buckley said the suggestion that unions would abuse that process to sign up unwilling workplaces is nothing but "fearmongering."

"Giving workers a fair opportunity to join a union is called democracy," he said.

Labour Minister Kevin Flynn said Monday that the government will make the report public in the near future, with plans to act on its recommendations. A government source said the report is expected to be released next week.

Flynn said the government will look at the union certification process closely to ensure that when workers make the decision to unionize, or not, they're doing so of their own free will without the government placing undue hurdles in the way.

Other issues covered by the Changing Workplaces review include benefits, work scheduling, vacation, sick time and sick notes, emergency leave and leave for those who experience domestic violence, and the issue of misclassifying employees as independent contractors so that they're exempt from labour laws.

Baldauf said businesses could adapt to some small changes to labour laws in those areas, such as making it mandatory for businesses to give all employees sick leave, but warned a major overhaul could have unintended economic consequences that ultimately lead to job losses.

"The problem is the government appears to be proceeding with broad legislative change without understanding the economic impact of these changes," Baldauf said.

Baldauf also said raising the minimum wage to $15 an hour -- a move supported by the province's unions -- could put some businesses in jeopardy, causing them to cut back on staff or increase prices.

Flynn, however, said raising the minimum wage isn't part of the Changing Workplaces review, although he wouldn't rule out doing so at some point. Currently, the minimum wage is set by legislation to rise with inflation and Flynn said he sees no reason to change that.

As for the other changes, Flynn said most successful employers already abide by the potential new rules considered in the Changing Workplaces review, as they offer benefit packages, vacation pay, and sick time.

"What we're trying to do is reward those successful, responsible employers by ensuring there's a level playing field and that level of dignity, respect and decency in the workplace is something that's expected of all Ontario workplaces," he said.

The government began the review more than two years ago and sought two labour law experts as special advisers. Those experts consulted with workers, unions and businesses to create their report and recommendations.

While the government has the final Changing Workplaces report, cabinet has yet to decide how to respond to its recommendations. Flynn said the response will include new legislation, regulations and government policy.