Ports of Auckland says a four day strike starting tonight will cost more than $1 million.

The strike over pay and conditions by members of the Maritime Union will close down the container terminals, affecting six ships and the flow of about 4700 containers.

Chief Executive Tony Gibson says the Ports of Auckland stake holders and customers understand the company's position.

"Essentially we want to make change, we want a step change, we want a continuous improvement programme, our customers are under pressure, cost pressure, and we have to respond accordingly but we want to do that in a collaborative style with the Maritime Union.''


Mr Gibson says striking in the busy pre-Christmas period is designed to cause as much havoc as possible and it's a tactic the union has used many times before.

The Maritime Union is accusing Ports of Auckland of breaching good faith bargaining.

Union president Garry Parsloe said the company was paying non union members more and offering them different conditions of employment.

"We don't want to sign another three-year agreement and have them making people redundant and taking people's jobs off them when the job should not be taken, and then imposing other people into those jobs, we just want a bit of honesty.''

Mr Parsloe says they gave a 24 hour strike notice and the company is locking them out for the remainder of the four days that the container terminal will be closed.

Members begin striking at 10:30pm tonight.