Commuters on Auckland's Southern and Eastern lines might have a slow start to their days after a crew issue spurred train delays and cancellations.
Auckland Transport said a "crew matter" near Otahuhu around 6.30 this morning caused delays and cancellations to Southern and Eastern line services.
Eastern line services were suspended between Manukau and Sylvia Park around 7am and passengers were being encouraged to switch to bus services.
Services started running again around 7.10, though commuters were being warned to expect delays.
Eastern Line services were running less frequently - every 20 minutes - throughout the morning.
The train troubles come amidst a week of expected commuter chaos, as bus drivers across eight Auckland depots are set to take part in rolling strike action.
Auckland Transport was warning its users there would likely be some disruption to services today.
First Union has issued a statement saying a strike between April 17-27 will take place in order for bus drivers to push for fairer pay and work conditions from NZ Bus.
Drivers at Swanson, Mt Roskill, Onehunga, Orewa, North Shore, Wiri, Panmure and city depots will take lower-level industrial action through striking.
Members will instead attend union meetings to decide a way forward following recent failed negotiations with the company. It is likely high-level industrial action will follow.
First Union said bus drivers' pay packets had borne the brunt of a council tendering process installed by the previous government that incentivises bus companies to cut wages in order to offer the cheapest tender to council contracts for bus routes.
Companies are struggling to get bus drivers and as a consequence of supply and demand need to pay employees significantly more to attract and retain drivers, it said.
The company is also attempting to cut overtime in new workers' contracts.
First Union organiser Graham McKean said Auckland bus drivers want an alternative to the Public Transport Operating Model (PTOM), and the issues that it has caused to be settled.
McKean said it was unfortunate that the morning strikes may affect commuters, but it was a last resort.
"We don't like disrupting services, but we have been in lengthy negotiations with NZ Bus and we simply have no other option so are encouraging commuters to leave home early, or arrange alternative transport."