With the strike entering its second day the port faces not being able to unload close to 14-thousand containers if they let the strike run until March 25.
Union members walked off the job early on Tuesday morning after mediation with Lyttelton Port Company failed.
Rail and maritime transport union organiser John Kerr says the port is busy spending money on lawyers to fight strike notices when they could be using it on their workers instead.
"They really need to have a good long look at themselves and say why don't we come to the table and negotiate."
He says they'll stop picketing tomorrow to see if the port company is serious about negotiations. He said striking port workers will call off their action for two days to enter negotiations with the port.