Workers at Auckland's largest bus company are threatening to strike next Friday, potentially affecting tens of thousands of commuters.
First Union is in a dispute with NZ Bus over pay and conditions.
It said the company was trying to undermine the bargaining process by approaching small groups of workers.
Union organiser Rudd Hughes said the company was also dragging out negotiations and its workers now wanted to take action.
"I'm just hoping that the people of Auckland can get behind us and put some pressure on the company to get back to the table and talk to us properly."
He said he understood passengers would be the meat in the sandwich but he hoped they would support the drivers.