The Maritime Union of Australia (MUA) has vowed to support their New Zealand equivalent for "as long as it takes" as protests are held at a Sydney port following nearly 300 Ports of Auckland redundancies.
The MUA were among several thousand people who marched in central Auckland - from Queen Street to Teal Park - on Saturday afternoon in protest of Ports of Auckland making 292 Maritime Union of New Zealand (MUNZ) members redundant following a lengthy industrial dispute.
At least 10 unions from around New Zealand, Australia and even the United States turned out in support.
Unions represented included the New Zealand Professional Firefighters Union, New Zealand Nurses Organisation, Australian Electrical Trades Union, Engineering and Printing and Manufacturing Union among others.
Mana Party leader Hone Harawira, Labour leader David Shearer and a representative from the Green Party were also present.
Protesters, some carrying small children, shouted: "Whose port? Our port" and "Two, four, six, eight, tell the council it's not too late".
Others held signs calling for the resignation of the ports chief executive Tony Gibson and Auckland mayor Len Brown.
Speaking to the crowds at Teal Park, beside the port, MUA deputy national secretary Mick Doleman said: "We'll be with you no matter how long it takes".
TV3 News reported union workers at a Sydney port were refusing to unload a ship that was worked on by non-union staff in Auckland.
Mr Doleman said MUA members were behind the Auckland port workers and offered $100,000 to the striking staff.
He said a public protest in support of MUNZ workers was held at the Sydney port.
The United States International Longshore and Warehouse Union (ILWU) vice president Ray Familathe said he represented thousands of stevedores along the west coast of the US who support MUNZ.
During a speech to crowds Mr Familathe hinted the ILWU may also refuse to unload ships in US ports if the dispute continued.
"We'll stick with them (MUNZ) all the way to the end," he vowed.
Earlier this week, the port sacked 292 striking workers after talks between the union and port management over a collective agreement broke down.
The union opposed the port management's plan to casualise the workforce and outsource jobs.