Aviation security officers say they are being worked to the bone, and to make matters worse, their latest contract offer takes away the valuable transport allowance.
It is a highly unionised work force - 85 percent of 800 staff - and collectively represented by the Public Service Association, E Tū, and the National Union of Public Employees.
The PSA's Wellington organiser, George Laird, said losing the allowance would feel like a "kick in the teeth".
The allowance was the same for all employees, no matter their role.
"It's a small amount of money to recompense them for their daily travel to the airport at all hours of the day, and some people will say other companies don't provide it, but we really see the loss of the allowance as a pay drop... it makes up part of a person's overall salary," he said.
But group manager of Aviation Security Services Karen Urwin said a fair buyout offer had been made.
"Many other organisations have been through this and very few still have a transport allowance. I should also add we pay for our own staff parking at the airport," she said.
The unions voted to strike at the end of last year but decided against it due to the Christmas rush.
Mr Laird said if members were to walk off the job, flights would be cancelled and there would be a nationwide standstill.
Ms Urwin hoped it would not come to that.
"We have an amazing workforce that works damn hard and I'd be really disappointed if things ended up with a strike, but we have contingency plans in place and we'd manage to the point where the public wouldn't see any difference."
Mr Laird said the unions would also rather settle a deal than strike, which would be the first in more than two decades.
But another issue employees want resolved was an increase in workload, especially in Auckland where 730,000 passengers - the highest ever - were screened last month.
"There's stress and if you go out to Wellington airport where there's limited screening, you'll often see queues going right back," he said.
Ms Urwin said the service was currently reviewing its staffing levels and increases could be made.
No aviation security officers were able to talk to RNZ because it would breach a confidentiality clause in their contract.
Radio New Zealand News
Updated at 8:39 am 15 January 2016