OTTAWA -- A union representing federal scientists and other professionals is demanding the government establish a separate pay system for workers shortchanged by the ongoing problems with the electronic system rolled out almost a year ago.

The Professional Institute of the Public Service of Canada says the patience of its members has run out and the government needs to introduce a separate, temporary system to pay those most affected by the Phoenix pay debacle until the problems are sorted out.

The government has said it continues to struggle with a backlog of about 8,000 cases of employees who have either been underpaid or overpaid supplemental pay, such as overtime.

In providing its latest update on the pay problems this week, Public Services and Procurement Canada stopped offering a timetable for when the system would be fully repaired.

Union president Debi Daviau says that was the breaking point for her, and the union no longer believes government promises that the system will be fixed any time soon.

The union, which represents about 55,000 public-sector scientists, medical staff and other professionals, says it continues to hear horror stories from members who are unable to pay their bills.