Hundreds more Northern Ireland civil servants than initially anticipated appear entitled to thousands of pounds in back pay, the Belfast Telegraph has learned.
Original estimates said around 9,000 — mostly female, low-grade civil servants — are in line for the payments but it is now believed the total is well over 10,000.
Their union, the Northern Ireland Public Service Alliance, is locked in negotiations with the Department of Finance but unable to tell members when the payouts might come.
But it has also launched potential legal action in parallel to ensure the money is secured.
Executive Ministers insist the Treasury should stump up the cash since the problem was first discovered and discussed under Direct Rule. The total cost will be in excess of £100m.
Those entitled to the cash include people who have since left the civil service, moved to other jobs or been promoted and could involve some sections which have been privatised. But it will be a huge administrative task to work out how much individuals are due.
Nipsa general secretary John Corey said: “This is money that is owed to civil servants and ministers have confirmed that it will be paid.
“We have entered negotiations to settle this matter and get the money paid as urgently as possible. Having said that, we recognise it is a complex process. I think it is going to take a period of months rather than weeks.
“We are committed to achieving a result to this by negotiation but at the same time we have to protect people legally. The legal advice we have obtained from senior counsel is that we have a clear-cut case. At the end of the day it comes down to legal entitlements.
“We as a union will be giving top priority to these negotiations but it is going to take some time because of the range of issues that have to be addressed.”
First Minister Peter Robinson and Deputy First Minister Martin McGuinness raised the issue with Prime Minister Gordon Brown in London last week and there have been two meetings between Finance Minister Nigel Dodds and the chief secretary to the Treasury, Yvette Cooper.
The issue goes back as far as 1999, however, when Nipsa first formally launched its claim and former Secretary of State Peter Hain is said to have agreed it must be sorted out.
Most of those entitled to the back pay are women and/or Catholics. Two-thirds were lower-grade civil servants, but it is now also believed to include typists and secretaries.