Exporters and shipping companies are fighting to block a Government crackdown on anti-competitive practices they say will be counter-productive.
In 2013, in a bid to prevent collusion among freight companies, the Government introduced the Commerce (Cartels and Other Matters) Amendment Bill. The legislation has yet to be passed.
At present, instead of ships from two separate companies sailing half full, the two combine and send one fully-stocked vessel.
Under the proposed law, such deals will need to be approved by the Commerce Commission, which Noel Coom of the International Container Lines Committee thinks will be expensive and impractical.
The arrangement applies in many countries and is known as a Vessel Sharing Arrangement( VSA).
Phil Bramwell of the Freight Forwarding firm Mondiale said it worked well, companies operating in this way were not colluding on price and a law change was not needed.
"Under this legislation they will actually have to get approval from the Commerce Commission at considerable cost to them to make any change (to their operations.) This could take three to six months which is not workable or practical."
Mr Bramwell said rather than face protracted bureaucratic debates, shipping companies could simply stop coming to New Zealand, which would reduce competition and raise prices for exporting firms.
Mike Knowles of the New Zealand Shippers Council represents companies such as Zespri that export commodities.
He said his organisation supported the intention of the cartels legislation but that VSAs must be able to continue.
He said while the legislation did not outlaw VSAs, the Commerce Commission could stifle initiative.
"The danger is that it becomes too bureaucratic and the risk is too high for shipping companies to make normal commercial decisions without getting a legal opinion and getting prior approval from the Commerce Commission."
Most objectors to this bill say it could end up costing shipping companies hundreds of thousands of dollars.
The Government rejects the criticism, calling its bill quality legislation.
Minister of Commerce and Consumer Affairs Paul Goldsmith said the bill would allow companies to collaborate if it enhanced efficiency.
But he pointed out offenders could face civil liabilities of tens of millions of dollars for corporations, or up to $500,000 for individuals.
Shipping companies fear being either caught out with penalties like this, or succumbing to slow bureaucratic procedures at the Commerce Commission to ensure their safety ahead of time, while goods lie on the wharves awaiting consignment.