TORONTO -- A memo sent to Ontario public service employees says the government is offering buyout packages to thousands of workers in an effort to cut costs without resorting to layoffs.

The memo, obtained by The Canadian Press and other media outlets, says the offer is part of the Progressive Conservative government's plan to address its fiscal challenges.

The document notes a buyout package has been available to unionized employees since 2013 but is now temporarily expanding to include other, non-union employee groups such as Crown counsel. Another similar package is being created for management, the memo says.

Those seeking to apply must do so between Jan. 1 and Feb. 28, and successful applicants must leave the public service before the end of next year.

A spokesman for Treasury Board President Peter Bethlenfalvy said Thursday that the offer will give the public service flexibility to "redeploy resources to priority areas where they are needed most."

"To be clear -- vital services to citizens will not be compromised by these voluntary initiatives," Hayden Kenez said in an email. "We are working hard to create a culture of productivity and efficiency."

Premier Doug Ford has repeatedly vowed that not a single job would be lost through government cost-cutting.

The buyouts memo was written by the head of the public service, Steve Orsini, and also sent to Ford as well as his chief of staff, Dean French.

"As part of the government's comprehensive plan to address its fiscal challenges, the government is exploring measures to manage its compensation costs in a way that ensures vital services to citizens are not compromised while avoiding involuntary job losses," the document reads.

Opposition legislators and labour groups said the premier is breaking his promise not to cut jobs.

"The Ford government's memo to thousands of workers makes it clear that Ford is eliminating jobs, and cutting the public services that everyday people count on," NDP legislator Sara Singh said in a statement.

"Doug Ford has not told Ontario families what services are being cut, or how many jobs he plans to cut. He has clearly been planning to slash jobs all along -- but has been making things up to hide it."

The Ontario Public Service Employees Union raised concerns the buyouts were only the beginning.

"I think we're up next, I have no doubt in my mind. I do worry about it a lot," said the union's president, Warren "Smokey" Thomas.

"I'm just quite concerned that they're going to keep cutting programs and keep cutting the front line by attrition and I tell you, the front line of the government has been cut to the bone."