OTTAWA -- The minister responsible for the problem-plagued Phoenix pay system says a backlog of outstanding transactions being dealt with by the federal pay centre has spiked to 520,000.

In a letter being circulated to federal civil servants over the next couple of days, Public Services and Procurement Minister Carla Qualtrough says those transactions include non-financial requests from employees, such as changing banking or home address information.

The number also includes 265,000 cases where government workers have been underpaid, overpaid, or not paid at all and have waited beyond what the government considers an acceptable period of time for their issues to be resolved.

In the letter, Qualtrough repeats what she and her predecessor in the portfolio have been saying for months -- that the situation is "unacceptable."

And she emphasizes that anyone working in government who is experiencing financial hardship as a result of pay problems can request an emergency salary advance.

Qualtrough says dealing with the pay system backlog will continue to be a slow process as the government seeks a "permanent solution" to the Phoenix debacle.

But she makes no mention of a call this week by one of the country's biggest civil service unions to build an in-house pay system and to scrap the system altogether.

The Professional Institute of the Public Service of Canada said earliuer this week that IT professionals already working within government can build and thoroughly test a new pay system within a year.