The Port of Tauranga's application to extend its wharves and shipping channel by dredging 1.8 million cubic metres of seabed will be heard in the Environment Court on Monday.

A panel of four judges will hear the case, which skipped the usual process of regional council hearings after it argued a decision on the proposed extension was an urgent national priority.

The company, which is 54 per cent owned by the Bay of Plenty Regional Council but publicly listed, says it will run out of capacity within three years if the extension to its operations did not go ahead.

It has already been declined by the Government's shovel-ready and Covid fast track infrastructure schemes, putting the project behind schedule, it says.

Given there may be delays via appeals from the Environment Court process, it needs an urgent hearing, it says.

'The port wishes to progress the resource consents as soon as possible, given the urgent need or capacity in New Zealand's supply chain and Port of Tauranga Limited ‘s (POTL) crucial role in resolving this as New Zealand's busiest port,” court documents say.

Without the development, New Zealand is looking at 'severe” capacity constraints on exports within a few years, the company says.

The Ministry of Environment declined the previous Covid-19 fast-track application saying it was more appropriate for the project to go through a standard consenting process, because there was a fair expectation submitters should be involved.

The port's application to the Environment Court showed the port applied for a resource consent for a 385m wharf extension and 1.8h reclamation at Sulphur Point, as well as wharf extensions of 530m north, and 388m south, of the tanker berth and a 2.9ha reclamation on its Mt. Maunganui wharves.

It says the associated extension to the shipping channel covers 14.4ha and involves dredging up to 1.8 million cubic metres.

The new development will allow the port to host several large ships at once, it says.

It notified the Tauranga Airport Authority and iwi about its plans in 2021.

Three submissions were received in response, two in opposition from iwi groups and one in support from the Tauranga Airport Authority.

A submission was also made by Ngāti He, who the port say was not notified, but had placed a submission nonetheless.

Documents show 10 iwi and hapū groups are party to the case, alongside the port and the regional council.

Hearings will run for 10 days, with half of those planned to be heard at Whareroa Marae.

If its application is successful, the port estimates the project will take nearly three years to complete, and cost $68.5m.

It's expected to create about 368 jobs in the construction phase and more than 81 permanent jobs after completion.

Tauranga port handles 42 per cent of New Zealand's container traffic, more than 850,000 containers a year.

Its previous application to extend, which included widening and deepening its shipping channels, was a four-year process, ending in 2013 when then-conservation minister Nick Smith gave the project the green light.

Smith says he granted resource consent after local iwi had blocked the plan under the old Resource Management Act.

The consent's conditions included restrictions on dredging, and the development of a Kaimoana Restoration Programme to mitigate the effects on local seafood especially the pipi beds, and extra funding for research.

-Stuff/Kirsty Johnston.