Transmission Gully, the $1.25 billion road out of Wellington, will not open on time.
Waka Kotahi transport services general manager Brett Gliddon today confirmed the road would not be ready to open by September 27.
The road's builder has advised alert level 3 and 4 restrictions and supply chain constraints associated with Auckland's lockdown have affected their ability to meet the contractually agreed opening date, Gliddon said.
"Work has resumed on the project under the appropriate health and safety protocols since the move to alert level 3, then alert level 2, in Wellington," he said.
"However these new delays, on top of the risk that already existed around achieving the contractually agreed opening date, mean it is clear that the motorway will not be ready to open on 27 September."
Transport Minister Michael Wood has already signalled the latest Covid-19 lockdown would likely affect the road's opening.
But as of Thursday, regional council officials were working on the basis the road would be opening in 10 days, with no word from the transport agency to say otherwise.
The troubled 27km motorway is being built through a public-private partnership (PPP), the Wellington Gateway Partnership (WGP), with CPB Contractors and HEB Construction subcontracted to carry out the design and construction.
It has already been delayed several times and blown its budget as a result.
Gliddon said Waka Kotahi and the builder were working together to understand the full effects of the lockdown and restrictions on the project, and confirm a new opening date.
"We know that people are keen to see the road open as soon as possible, and everyone is working as fast as they can to get the road open to the public."
This week Greater Wellington Regional Council (GWRC) chairman Daran Ponter was frustrated by the lack of communication about the road's opening.
On Thursday he said nobody had officially made a call on whether September 27 was a goer, nor given any indication of what plan B looked like.
"And the answer to that question about the date lies between what must be some fractious negotiation between NZTA Waka Kotahi and the road builder,@ he told the Herald.
GWRC acts as the environmental regulator in relation to the road and is dealing with a number of outstanding resource consents, which need to be signed off for Transmission Gully to legally open.
Council officials had already raised concerns about whether 44 tasks could be signed off in time for the road to open even before the Covid-19 lockdown.
In an update this week they said retrospective consenting remained the "biggest red flag" for road opening.
As the council is yet to even receive an application for some of these consents, which can be complex, officials consider it "entirely unrealistic" they'll be processed by September 27 anyway.
The builder was going to be liable for $250,000-a-day in damages if the road didn't open on time.
Furthermore, $7.5 million of a $145.5m settlement covering the cost impacts of Covid-19 was not going to be paid out if the road was late.
But alert levels 3 and 4 are considered a force majeure event. This relieves an affected party from contractual obligations because of an event outside of its control.
WGP and Waka Kotahi will provide an update on "plan B" once the additional time required to complete the road for public use has been agreed.
Waka Kotahi has advised there will be no further comment until then.