Some workers at the port of Lyttelton will begin continuous strike action on Friday night.
Pay negotiations between port management and the Rail and Maritime Transport Union have stalled, and logistics staff will walk off the job every night from 11pm until 7am indefinitely.
They will also start ensuring they take their breaks during the day.
The union's South Island organiser John Kerr said the union had also given notice of a total withdrawal of labour on 17 and 18 May.
Mr Kerr said its members were seeking a 4 percent increase over 12 months, while management had offered 2.85 percent.