OTTAWA -- It's unlikely that any single person will be held accountable for the government's failed employee pay system, a senior federal bureaucrat told a news conference Wednesday.

The costs of dealing with the pay problems will also likely continue well into the new fiscal year, which begins April 1, said Marie Lemay, deputy minister of Public Services and Procurement Canada.

The department continues to struggle with a backlog of about 8,000 cases of government employees who have experienced problems with their paycheques, ranging from being underpaid to being overpaid -- or not being paid at all.

About 5,000 of those files have been partially resolved but are not yet completed, said Lemay.

And while resources are focused on clearing that backlog, the government has been unable to meet its 20-day standard deadline for new, incoming pay changes and requests, said Lemay, who has been the public face of the department since last summer when it faced a backlog of about 82,000 cases.

Many of the remaining files are "complicated," Lemay said, adding that some cases are taking a full day each, or longer, on average, for pay system employees to rectify.

And that has meant it takes about two-and-a-half months longer than it should to deal with incoming pay requests.

"That's very frustrating," said Chris Aylward, national executive vice-president of the Public Service Alliance of Canada, which represents the majority of federal civil servants.

"In the last 48 hours I was still getting emails about people not receiving proper pay," he said.

The deputy minister said Treasury Board will take the lead in investigating what went wrong with the Phoenix system, which was launched early last year with the double goal of moving away from the government's antiquated paper-based pay system while saving money.

But she expressed doubts that any individual would face repercussions as a result of the failed launch.

"In projects like this, especially with an organization like ours, when you have the equivalent of 100 companies implementing a system ... there's going to be ... multiple points of failure," said Lemay.

"If the hope is to find one person (responsible), I don't think that's going to happen."

Lemay added that the auditor general will conduct a separate evaluation.

At its last briefing in December, the department said about 10,000 cases remained in the backlog of current and former public servants being paid improperly.

As well, the overall cost for fixing the computerized pay system was expected to exceed $50 million.

That cost will likely continue to rise as the government retains employees hired to operate a call-in centre and process claims for several more months, said Lemay.

Before the system was launched, the previous Conservative government had banked on it saving taxpayers $70 million annually.

Both Aylward and Lemay said the government and unions are working closely to ensure that lessons learned from the Phoenix debacle are applied to any new, major government programs affecting federal employees.