The federal government says it won't scrap the troubled Phoenix pay system, despite its costly problems and criticisms from the auditor general.

Marie Lemay, the deputy minister responsible for fixing the system, told a Commons committee today her department has no choice but to attempt to stabilize Phoenix — at least in the short term.

Lemay says the Public Services and Procurement Department must work with Phoenix because there is no plan B.

Lemay made the comments as she, other government officials and auditor general Michael Ferguson testified at the House of Commons public accounts committee.

Union wants new system

Ferguson last week issued a blistering report on Phoenix, warning that stabilizing it will take years and cost more than $540 million.

Committee chairman and Conservative MP Kevin Sorenson, who represents a rural Alberta riding with few federal civil servants, says his constituency office has recently received more calls on Phoenix than any other file, including immigration.

One of the biggest federal civil service unions has called on the Liberal government to scrap Phoenix and build an in-house system virtually from scratch.

The auditor general says about 150,000 government employees — about half of the federal workforce — have faced pay problems since Phoenix was launched in April 2016, including being underpaid, overpaid or not paid at all.