As part of the action, drivers would not sign on before their rostered shift starts, from 4am tomorrow until 4am on Friday next week.
"To prepare for their shifts drivers must arrive early, but this time isn't considered work time even though they are carrying out duties necessary for their work," Mr Hughes said.
First Union has accused Howick & Eastern of trying to remove weekend and overtime rates, which the union said was at the heart of the issue.
"Drivers often have to work over and above their rostered shifts and they deserve to be paid for the time that they lose with their families, friends and in the community."
The action will also include drivers refusing to drive buses with known safety defects, buses with a defective Hop card reader or ticketing machine, and buses without a working radio telephone or warrant of fitness and road user certificate.
The industrial action follows a victory for Auckland bus drivers after the Employment Relations Authority found NZ Bus had breached consultation requirements.
The bus company has been fined $10,000 and ordered to meet its obligations to consult with unions.
Employment Relations officer Vicki Campbell found NZ Bus did not give union delegates enough time to discuss new rosters with drivers before starting them in July last year.
The new rosters had rotating shifts requiring shifts of up to 10 or 11 hours at a time, often with only 10 hours' break in between.
Many drivers would be moving from fixed or only partly rotating rosters to fully rotating rosters with long stretches of weekend work.
The union argued this would have a significant impact on drivers' work/life balance and needed to be discussed and understood by workers.
"This decision reinforces our view that Auckland Transport's [AT] model is broken," said First Union transport and logistics secretary Karl Andersen.
On February 19, NZ Bus drivers in Auckland went on strike, demanding better pay and work conditions including toilet breaks and break periods between shifts. The dispute has been settled.
