More than 1300 Air NZ workers will lose their jobs as the airline starts cutting affected routes.
Long-haul and mid-haul staff will lose 950 jobs out of the 1600 roles affected, the union E tū says.
Three hundred domestic crew will also be laid off across Auckland, Wellington and Christchurch.
And 97 staff will lose their jobs at regional airlines Air Nelson and Mt Cook Airline, the union said.
One E tū cabin crew member said staff were "absolutely devastated".
"Having seen first-hand the work done by our union members, and still having this result, is crushing. Air New Zealand values its staff less than its profit and shareholders, which so sad to see unfold.
"The company's process has been rushed, overbearing, heavy-handed, and uncompromising. I don't believe the feedback in the consultation process was ever truly evaluated or applied."
E tū assistant national secretary Rachel Mackintosh said "many more workers are also devastated".
"It couldn't be much worse for some of Air New Zealand's loyal cabin crew," she said.
"Many are completely gutted – they have committed years to making Air New Zealand a world class airline, only to be out of work with huge uncertainties about ongoing careers in their industry."
Mackintosh said the union had been calling for a better process at Air New Zealand since the Covid-19 crisis began.
"E tū is calling for Air New Zealand, other companies, and the Government to rebuild better – making sure we keep and create decent jobs and have union members involved in all decisions.
"Air New Zealand employees need the company to be much more transparent, accommodating, and compassionate if they are to build their way back to being a strong national carrier."