'Far too long' for Spirit of Tasmania replacement costs to be known: Labor

Shadow Treasurer Josh Willie repeated the accusation first made on Wednesday, that the Premier had breached parliamentary and ministerial codes of conduct.

"We can't have the Premier of Tasmania deliberately misleading Parliament and Tasmanians because it's politically inconvenient," Mr Willie said.

"We knew that there'd been a cost escalation, we asked repeatedly in Parliament. They did not come clean until Parliament rose.

"Yesterday, it was revealed that the government knew full well that the cost had increased because they'd approved an increase in the loan facility for the Spirit of Tasmania upgrades and the wharf upgrades to make sure that that job can get done."

The Public Accounts Committee heard on Friday, June 28 TT-Line executives initially rejected a request by shipbuilder Rauma Marine Constructions (RMC) for an extra 50 million euro payment ($81 million) for the ships, and instead offered an extra 30 million euro ($48.5 million).

A loan facility extended to TT-Line was increased from $700 million to $990 million in December 2023, and the extra 50 million euro payment to RMC was approved in March.

The committee heard Treasurer Michael Ferguson was informed of both developments.

Earlier in the week, it was revealed the cost of upgraded berthing facilities at Devonport - necessary for the new vessels - had ballooned from $90 million to $375 million over five years.

The government denied the cost of the wharf upgrade had risen to $350 million during question time in May.

A government spokesperson said the revised estimate was not available at that time.

Mr Willie said TT-Line representatives deserved "credit where credit's due" for fronting the inquiry, however the information had been withheld for too long.

"It has taken far too long for that information to be in the public domain," he said.

"It could have been a much more proactive approach keeping Tasmanians informed."

Lyons MHA Guy Barnett said the Premier had answered questions over the wharf "consistent with the information he had at the time".

Mr Barnett said TT-Line's business dealings were being scrutinised appropriately, and touted the benefits of the two new ferries.

"[TT-Line] are operating for, and on behalf of, all Tasmanians, they are a government business enterprise and their decisions are very important," he said.

"We will be having the Spirit upgraded by 40 per cent, which is fantastic.

"They have to be accountable, and that happens during government business enterprise scrutiny hearings ... I'm sure there'll be more questions in due course during those scrutiny hearings."