OTTAWA -- Federal officials say they expect to have resolved all of the pay delays created by the government's problematic Phoenix pay system by the end of October -- but undoing the damage won't be cheap.

Dealing with the months-long debacle, which has caused serious payday headaches for tens of thousands of civil servants, will cost an estimated $15 to $20 million, deputy public works minister Marie Lemay told a news conference.

That doesn't include upgrades that will be required to ensure the system runs more smoothly in the future, she added. "There's another portion that we're looking at doing to enhance and that I still don't have a cost to."

Some 1,100 of the more than 80,000 problem files identified last week have been closed, Lemay said.

That includes the 486 government workers who were provided with back pay on Wednesday after having gone for months without compensation.

Another 234 employees listed by officials as "Priority 1" cases will see their paycheques in two weeks, Lemay added.

A second priority group -- workers going on maternity leave, long-term disability leave or retiring -- will see their files handled within four to six weeks, the deputy minister said.

Another category of civil servants that includes employees owed overtime or who have seen their employment terminated will be processed by the end of September, said Lemay. Those who have been overpaid, promoted, are on planned leave without pay or are owed deductions or benefits are at the back of the queue.

Curiously, 60 people who reported they had not been paid were not in the government's system at all. Lemay would not speculate on why their information was missing but encouraged anyone with outstanding issues to report to the government a second time.

To speed up the process of eliminating reported pay holdups, the government is opening satellite pay offices in Winnipeg, Montreal and Shawinigan, Que., as well as hiring more staff in Gatineau, Que.

"We've hired more people and we're adding more temporary pay offices," said Lemay.

"To accelerate our progress, we are recruiting as many compensation experts as we can to help employees get paid as quickly as possible."

On Wednesday, Public Services and Procurement Minister Judy Foote paid a personal visit to the government's central pay centre in Miramichi, N.B., where officials confirmed that dozens of employees are on stress leave linked to the pay system issues.

The Phoenix system oversees the payment of 300,000 federal public servants. More than 80,000 workers have either been overpaid, underpaid or missed entire paycheques since Phoenix launched in February.

The House of Commons government operations committee is also holding an emergency meeting later today to examine the Phoenix problems.

Last week, the federal privacy commissioner announced a formal investigation into a privacy breach linked to Phoenix earlier this year.

Auditor general Michael Ferguson will also review the planning and implementation of Phoenix; 13 public service unions are asking the Federal Court to rule that the government must pay public servants properly and punctually.