Up to 40 security staff at Belfast City Airport are facing a cash-strapped Christmas after being paid hundreds of pounds short for the past three months.
Many of the security workers lost out on more than £1,000, with some of them forced to max out their credit cards just to cover monthly bills.
The issue arose after Mitie, a security firm, took over a contract held by G4S in November.
A spokeswoman for the company told the Belfast Telegraph: "We're working hard to resolve any pay issues as quickly as possible.
"We can confirm that everyone was paid the correct amount for this month, and any money owed to our people will be paid to them before Christmas."
A worker at the company, who asked to remain anonymous, told the Belfast Telegraph he had lost more than £1,200 and Christmas had been ruined.
"People have lost out on thousands since October because we haven't been paid the correct amount," he added.
"I've been paid incorrectly and lost £1,200 over the [past] three wage packets, but there's far worse than me.
"The airport said they would sort it out last month, but they haven't bothered.
"It's a week before Christmas and we are worried sick. This will ruin our Christmas."
The worker told how in October's pay packet, employees were short by some £380. This was followed by a further loss of £300 in November and another £500 this month.
He added that all of Mitie's employees at the airport have been affected by the error.
Staff were initially told that it would be resolved by Christmas, however representatives have now said it will be the end of the month before the pay issue can be fixed.
The worker, a dad-of-two, said he was devastated he could not buy his children the Christmas presents they wanted.
"Staff are ready to walk out," he added.
"I have bills and a mortgage to pay, but I won't be able to pay it this month because I haven't got the money. Christmas this year will be bad - we can't buy what we planned. I had to use my credit cards last month to replace what they didn't pay me and now they are maxed out.
"We are not allowed to contact the Mitie office directly. People are going crazy over this.
"There's nothing we can do and we feel the next step is contacting a solicitor, and we are seriously considering it because they aren't doing anything for us.
"The company have made all these promises, but no one has got anything. You wouldn't even think it's Christmas in work, and you would never see anywhere with morale so low."