Lyttelton Port in Christchurch has won an injunction to force Maritime Union workers to unload a container ship due to arrive on Wednesday.
In a show of support for their northern counterparts, hundreds of union members planned to boycott the Lisa Schulte because it had been handled by non-union labour at Ports of Auckland.
Lyttelton Port chief executive Peter Davie said there was no positive outcome from his discussions with the union on Wednesday morning.
"They have a national position that they're following, we understand that, but from our side it is not a dispute in Lyttelton, it's a dispute in Auckland," he said.
The company sought an injunction from the Employment Court to ensure that the ship is unloaded.
A judge on Wednesday night granted this, but ordered mediation between the two parties.
The Maritime Union says it is disappointed at the decision but has asked the 150 or so members on the picket line to comply with the injunction.
Similar union action over the past week has failed, with Employment Court rulings forcing Wellington workers at CentrePort to load and unload the Maersk Aberdeen and Tauranga port staff to work on the Irenes Remedy.
The president of the International Transport Workers' Federation (ITF), Paddy Crumlin, who is based in Australia, says the Auckland port dispute has drawn negative attention internationally.
Mr Crumlin told Morning Report that the ITF has declared Ports of Auckland a 'port of convenience' which in union terms identifies it as one of the worst ports in the world for industrial relations and employer behaviour.
"If shipping companies want to go there, it has ramifications with dockworkers and seafarers aboard their ship and dockworkers at other ports they go to."