Air New Zealand engineers are planning to go on strike just four days ahead of Christmas in a move which could bring huge disruptions to travellers' holiday plans.
The airline's engineers are planning to strike on 21 December, the busiest day of the year for travel.
Close to 42,000 customers are booked to travel domestically and internationally on that day.
The Aviation and Marine Engineers Association (AMEA) and E tū unions, notified the airline yesterday evening of a total strike by almost a thousand unionised employees. The unions have also advised Air New Zealand to expect further industrial action.
"Close to 42,000 customers booked to travel domestically and internationally on 21 December alone now face potential flight cancellations," Air New Zealand said in a statement.
"The average income of the maintenance engineers, logistics and other staff to strike is $115,000 - more than double the average wage in New Zealand - and around 170 of them earn more than $150,000.
"While the group has received pay increases annually for the past 12 years, it has so far rejected recent proposals by the airline including an immediate 2 percent pay increase followed by a further 3 percent increase after 12 months, with a further pay review in mid-2021."
Air New Zealand General Manager of Aircraft Maintenance Viv de Beus said the news was "extremely disappointing".
"We know how important summer holidays are for our customers who look forward to being able to gather with friends and family at this important time of year," she said.
"It would be devastating to see the holiday plans of more than 40,000 hardworking Kiwis and international visitors ruined.
"We have only been in negotiations with this group for six weeks so industrial action is entirely premature.
"We remain committed to working closely with the engineers' unions to reach a reasonable agreement and avoid strike action if at all possible."
Air New Zealand said it will remain in contact with customers booked to travel on 21 December.
E tū said in a statement they were disappointed with the "misleading" information Air Zealand had released regarding the strike.
"No one wants to disrupt people's Christmas plans, but Air New Zealand has taken an unnecessarily aggressive approach.
"This is not just about pay. This is about repeated proposals by the airline weeks out from Christmas to pay them less than colleagues who have already settled, and to cut into key conditions, including overtime rates.
"This affects line and hangar engineers, but also store workers and aircraft cleaners, who are covered by the same document and who are struggling to get ahead.
"Our members feel under-appreciated and under attack. The ballot results show an overwhelming resolve to take action to defend themselves.
E tū said taking strike action was extremely rare for Air New Zealand union members.
"Aviation workers don't make these decisions without good cause. In aviation, there is a constant downward pressure on costs driven by airlines. The result is a race to the bottom on wages and conditions.
"New Zealand needs to remain a high-wage high-skilled economy. Aviation is a life blood industry.
"We will be in mediation with Air NZ Engineering management first thing on Monday and will carry on bargaining in good faith in the hopes of reaching a deal," the union said.