OTTAWA -- Two years into the Phoenix pay system "fiasco," the federal government needs to apologize to the tens of thousands of civil servants who have been living a paycheque nightmare and compensate them for what they've lost, the opposition New Democrats demanded Monday.

The demands coincided with the second anniversary this week of the launch of the troubled electronic compensation system, and come in advance of Canada-wide protests planned for Wednesday.

It's outrageous that, after 24 months in which civil servants have been underpaid, overpaid or not paid at all, the government still doesn't have a solution, said NDP finance critic Peter Julian.

"We've had public servants, who are working for the people of Canada, who have lost their home," Julian told a news conference in Ottawa. "We've had public servants who have been unable to put food on the table for their families."

An apology won't bring back the cars and homes that some public servants have lost after not being paid, but that doesn't diminish the importance of formally declaring that government employees endured something that should never have happened, he added.

Julian introduced a motion Monday calling for an apology and compensation. A vote on the motion was expected Wednesday.

"The only way, as part of our motion, we think the government can truly atone for what they've done is by a formal apology in the House of Commons."

The Phoenix pay system was meant to centralize and streamline pay systems across several dozen government departments and agencies since being brought online in February 2016.

Instead, it has resulted in endless headaches for civil servants, both working and retired.

While the former Conservative government contracted the Phoenix system, the current Liberal government launched it, and both parties have blamed each other for creating the mess.

Public Services and Procurement Canada Minister Carla Qualtrough did issue an apology of sorts Monday on behalf of the government, much as she has done before. But she defended the decision to launch Phoenix, assigning much of the blame to her Conservative predecessors.

"Of course we sincerely apologize to public servants for everything we've put them through as a government," she said during question period. The government had to choose "between a new system and no system" after coming to power, she continued, because the "previous Conservative government had fired compensation advisers, had decommissioned the former system."

Two years ago, senior officials advised the government that Phoenix was ready to go live, she added.

As of late January this year, the backlog of problem files created by Phoenix had reached 633,000 cases; cost estimates for dealing with the errors now range from $1 billion to as high as $5 billion.

The tally reached nearly $788 million earlier this month after the government asked Parliament to approve $76.3 million in new anticipated spending before the end of the current fiscal year. That was on top of the initial $309 million used to set up the troubled system and $402 million the government announced last May to bring the Phoenix system to a so-called "steady state."

Unions representing more than 300,000 civil servants have organized protest rallies across the country for Feb. 28 -- the anniversary date of the launch of Phoenix -- under the banner "Burnt by Phoenix" that are expected to include "triage tents" where civil servants facing pay issues can turn for help.

While some government employees have called for work stoppages as part of Wednesday's demonstrations, union leaders have pointed out workers must, under the terms of their collective contracts, report to their jobs as scheduled.