The Malinauskas Government foreshadowed at the State Budget its concerns the price of the final stage of the mammoth South Road tunnelling project could increase amid rising infrastructure costs across the globe.

But Koutsantonis said an unsourced report by The Advertiser on Thursday that the project cost will escalate to $14 billion was premature.

“I don’t know, I haven’t been advised officially from the department,” he told ABC Radio this morning.

“I wouldn’t be surprised if there are increased costs, the reference design work that was done by the previous government had a lot of failings and I think one of those failings were cost estimates.

“It’s fair to say that the $9.9 billion number touted by the previous government was optimistic to say the least.”

Koutsantonis said he would receive a cost estimate from the department in “weeks, not months”.

“My department hasn’t given me a cost estimate yet, all they’ve given me is from the day I’ve got sworn in till today is serious warnings about the reference design and the cost estimates that were in place when we came into office,” he said.

“We’ve got now people who are working on the North South Corridor who built every other part of the North South Corridor. They were excluded from the designs of the tunnel.

“They are now working on and they’re raising serious questions with me but I haven’t been given a final number.”

Asked whether he was still committed to the project, Koutsantonis said:  “If we don’t fix the North South Corridor between Anzac Highway and these roads getting people to the city, the grid will grind to a halt.”

“We do need to do it and the best way to fix that portion is with a tunnel there’s no doubt about it.”

The cost of the Torrens to Darlington stage of the North-South Corridor blew out from $8.9 billion to $9.9 billion under the former Marshall Government.

The project requires the acquisition of just under 400 properties. It’s completion year has also been pushed back to 2031.