Work on Wellington's billion dollar Transmission Gully project has been drastically curtailed as the completion date is delayed again.
Many of the roading sub-contractors are no longer employed and the opening is being extended into 2021.
The Transport Agency had confirmed it was trying to negotiate a new completion date with the joint venture consortium building the four-lane highway.
It blamed the Covid lockdown for the latest delay putting this year's November deadline on hold.
"Waka Kotahi NZ Transport Agency is committed to seeing the Transmission Gully project completed as quickly as possible," it said in a statement.
"It is clear that the level 4 lockdown and level 3 restrictions will have an impact on the completion date which will likely extend into 2021."
The agency confirmed there are 182 staff currently working on the project which usually has a team of more than 700.
It said about 80 key people are still overseas because of Covid-19.
"A significant portion of the site engineering and supervision team and some of the operations personnel are still at home overseas, including slope stabilisation crew members and paver operators, and are unable to return to site with current border restrictions."
Road Transport Forum's chief executive Nick Leggett said he could not understand why five weeks of tools down would delay the project by over a year.
"It was originally supposed to be the end of this year, it's a worry that just four or five weeks of a Covid-imposed stop to work could push the project out for months or even years."
Subcontractors working on the 27 kilometre route have told RNZ the project would shut down for the winter months, and best case scenario, they could be back on the job in September.
One said he had been told he could remove his equipment from the site completely as there was a possibility the project may fall over altogether and have to go back out to tender.
The Transport Agency said it was working on a new delivery plan but until it is finalised many people and bits of equipment were unable to be utilised.
National's transport spokesperson Chris Bishop said the extended delay could not just be because of the Covid-19 lockdown.
"You gotta wonder what on earth is going on here where a month's worth of lockdown, where quite rightly no construction work could take place, has essentially meant a potential one to two year delay on critical infrastructure for Wellington and New Zealand.
"It just doesn't make a lot of sense.
"Obviously people would expect a construction halt while the country was in lockdown, but I think it speaks to wider issues about the way the project has been carried out," he said.
Bishop said contractors were disheartened and they did not believe they would be back on the job, or delivering the new road anytime soon.
Bishop said they needed clarity from the government.
Nick Leggett said NZTA had left lots of questions unanswered, and their silence was telling.
"There has been an air of secrecy around the Transmission Gully construction from the beginning, and for those of us who have followed it and been watching on the periphery, this is no surprise, the lack of clarity and the seeming lack of wanting to give a specific answer about the completion dates, budgets and the work on the project."
Previously the Transport Agency had said the consortium could be fined up to $16,000 for every day over the completion deadline.
The agency would not confirm if the new deal would include penalties.
The joint venture partners, CPB and HEB both declined to comment, stating they were prohibited by their contract to do so.