Auckland's train services will be disrupted for three weeks from Monday as train drivers and crew take industrial action.
The Rail and Maritime Transport Union (RMTU) says it's concerned passenger safety will be compromised if Auckland Transport and Transdev remove train managers from service .
"We are saying that (removing train managers) is not safe and it will compromise passenger safety," says RMTU organiser John Kerr said.
Train manager are responsible for safety and security and are a deterrent to anti-social behaviour, are first responders to trackside emergencies, among other duties, he said.
"Auckland Transport say they'll have transport officers roaming the network that will provide that service but there won't be enough of them to have a uniformed member on each train - we don't want to inconvenience the public (with the strike ) but we won't have an unsafe rail network."
Train services on the eastern, southern and western line will be running at a reduced frequency from February 26 to March 16.
Auckland Transport and Transdev say that they have developed a temporary timetable to minimise disruption and provide consistent rail services on these lines during the next three weeks.
Southern, western and eastern line weekday peak train services will run at 20-minute intervals, with inter-peak and off-peak services running as normal.
Many trains will run with six cars - which can hold 900 passengers - to help reduce impact.
Onehunga and Pukekohe weekday train services and weekend train services across all lines will remain on their usual timetable. Ferry and bus services will operate as normal.