Wellington train passengers could face disruptions on Tuesday as staff begin work-to-rule industrial action from Tuesday, ahead of contract talks.
Metlink said workers had voted to take all breaks and not work overtime or accept alterations to their shifts.
Spokesperson Samantha Gain said passengers should plan ahead because train services could be cancelled or delayed at short notice.
It was hard to predict which services would be affected, she said, but limited bus replacements would be available for cancelled trains.
Where possible, rail passengers should find another way to travel, she said.