Cook Strait ferry workers are to strike over a breakdown in talks about working conditions.
Talks between KiwiRail and the unions representing workers, the Merchant Service Guild and the Aviation and Marine Engineers Association, broke down on Friday.
The unions have issued a 14-day notice of strike action on the Interisland ferries beginning on 1 December. KiwiRail says sailings of all three ferries including cargo and passengers will be suspended during that time.
The unions have been negotiating with KiwiRail since February this year.
Merchant Service Guild president Lewis Henderson says the company has offered the workers a small pay rise, but talks broke down over service entitlements.
He says those allowances are important to service entitlements for some workers who spend a week on board the ferries at a time.
"They work 12 hours per day for that whole week and in the other 12 hours they're not only captive to the workplace, but they're also captive to being able to see their family, they're not able to leave."
Mr Henderson says that means the workers are essentially working 168 hours a week and KiwiRail wants to remove the allowances that compensate for that.
He believes the strike will affect many people leading up to Christmas, but workers did not plan the timing.
"It will cost. There is freight that travels on a daily basis across Cook Strait. Some of the freight is important and needs to move, including perishables. There will be an impact on people as well. We don't take this lightly - this is a last resort for us."
Lewis Henderson says the unions hope KiwiRail comes back to the negotiating table with "a proper attitude" before the strike takes place.