The union for Auckland train engineers is warning that the city's commuters face significant disruption because of a 30 day strike that has started this morning.
The Rail and Maritime Union said 36 engineers had been locked out by their employer, CAF NZ, after issuing a strike notice last week.
Northern region organiser Rudd Hughes said the largely migrant workers were paid 13 percent less than those doing similar work for other companies, such as KiwiRail, and they wanted parity.
He said before being locked out by CAF NZ, the engineers had opted to do a partial strike which meant they would do preventive work on trains to make sure they were safe, but would not carry out any corrective work on the units.
Mr Hughes said commuters might not be affected by the strike initially, but after three or four days without engineers to maintain the trains, there would be disruptions.
Auckland Transport said they had not been told by CAF NZ that the workers had been suspended and it was business as usual.