A health care union is challenging the Saskatchewan government's move to have a private clinic do surgeries to cut down on waiting lists.

On Monday, the Regina Qu'Appelle Health Region said it is booking knee and dental surgeries at the Omni Surgery Centre in Regina.

The province said the initiative will help cut down on backlogs and will be paid for out of the health care budget. However, the Canadian Union of Public Employees says its collective agreement restricts the health region's ability to contract out services. It says it's taking the matter to an arbitrator later this month.

The province say surgeries done at Omni Surgery Centre cost less than the same procedures done at a hospital.

Knee surgeries will cost $1,500, saving the government $179 or 11 per cent per procedure, while dental surgeries, at $965, will be cheaper by $76 or seven per cent, the Health Ministry said Monday.

However, CUPE disputes those figures. It says Saskatchewan pays less than $1,000 for knee surgery when they have the same surgical procedure done in a public facility in another province.

For example, the Ontario Health Ministry's website shows the public cost is $997 per day surgery, CUPE said.

The union says the money the province will be sending to the Omni company would be better spent expanding the public system to provide more day surgeries and diagnostic tests.