Auckland train commuters face massive delays for the next month as the dispute between railway workers and their employer continues.

Train maintenance and repair crews threatened to walk off the job for 30 days from tomorrow, calling for fairer wages from their employer Construcciones y Auxiliar de Ferrocarriles (CAF).

However, instead of negotiating with their workers, the Rail & Maritime Transport Union alleges CAF has effectively locked out their employees for the next month, saying any one who strikes will not be paid.

"These skilled and dedicated people make it possible for the trains to run on time, and all they want is to be paid the market rate," RMTU organiser Rudd Hughes said.

Advertisement

"When we get on board a train we assume it'll be a safe journey, and when we arrive safely at our destination we have them to thank.

"If CAF workers are prevented from safely maintaining Auckland's trains, those trains will stop moving."

CAF has been approached for comment.

Auckland Transport said CAF has not advised them about any lockouts and staff were scheduled to work regardless of union membership or not.

However, as a contingency plan AT could cut the number of seats on trains by half during peak-hour travel times.

Some trains might only have three carriage sets rather than six from tomorrow until midnight on Sunday, June 9.

And when necessary, some services could be cancelled.