The union representing nearly 1700 Air New Zealand service staff whose jobs are under threat is to investigate the airline's claims that using a third party contractor could save it $20 million annually.
The airline said it was being forced to look at replacing or restructuring the airport services division unless it could become drastically more competitive.
Engineering, Printing and Manufacturing Union national secretary Andrew Little said Air NZ had already taken steps to investigate other options.
"We understand the airline has a preferred contractor already lined up," Mr Little told National Radio this morning.
"We understand the bid is on the basis that the large bulk of existing staff would transfer over, but it would be on lower wages and conditions."
He said it was possible the move could simply be a convenient way of cutting wages, and would meet with members over the next couple of weeks to discuss it.
Outsourcing had historically been used as a way to cut costs.
"One of the key issues is to get the relevant information that underpins what the airline has put on the table," Mr Little said.
He said there was an option of using a 58-day process, where the airline was under obligation to provide relevant information.
"We'll explore that process. The critical thing is for us to get the information so we can gauge how genuine the $20 million savings actually are."
He said he wasn't aware which company Air NZ had been talking to about taking over the airport services division.
"At the very least we need to know what the details of their bid is so we can gauge how genuine and achievable the claimed savings are -- that's critical -- but we don't necessarily need to know who they are."
But Mr Little said the workers themselves eventually needed to know who they could end up working for, and at what price.
He wouldn't say whether or not he believed Air NZ's cost saving claim was genuine.
The airport services division manages processes ranging from check-in to tarmac operations and loading luggage for Air New Zealand and many other airlines in the country.
It employs 1675 full and part-time staff based at Auckland, Wellington and Christchurch airports.