The port company warned more than a year ago that imports and exports risked being severely constrained with consequences for the economy if the two-year construction project wasn't started soon.
Sampson said the cost of the project, put at around $68 million in 2020, had since inflated by $20m.
The port is New Zealand's biggest and the main gateway for exports. With the main imports port at Auckland under-performing during the Covid-driven supply chain crunch of the past two years, the Tauranga port has also been called on to handle diverted import vessels.
It asked for the Environment Court hearing in May last year. The request was accepted in December.
The hearing, which has attracted objections, was due to last 10 days.
Detailed planning and consultation for the wharf extension started in early 2019.
The port's May 2020 application for the extension to be considered a "shovel ready" project was knocked back by the Government in March last year.
Its application in October 2020 to the Government for "fast track" status under the Covid economic response was also rejected six months later.
The Ministry of Business Innovation and Employment suggested in April last year the port take the direct referral route to the Environment Court.
Sampson said the application to the shovel-ready scheme was made in 2020 "because of the urgency and capacity constraints we were facing".
"Had we been successful, we would be finishing construction now for a cost of around $68 million.
"Yet here we are, having had no success in even getting an Environment Court hearing."