That's the conclusion of the announcement from Willis and Peters.

Willis maintained Cabinet's funding had been committed, coming from next year's Budget. She believed Cabinet had a "clear view" of the maximum costs of the project and said she wanted to come in much lower than that.

Peters said if the Government couldn't have done better than $4b, he wouldn't have taken on the job in the first place.

"Does this look like a blow-up? This is not a blow-up," Willis said to suggestions the coalition parties had long disagreed about what to do about addressing the ferry situation.

Willis expanded, accepting it was fair to say that some in the coalition held "divergent views", noting some thought investment in ferries wasn't necessary at all. 

Willis, describing the new ferries, said: "These will be reliable ships that are appropriate to our means."

"It's drivel," Peters said when speaking to why the Government won't respond to reports the cost of the new ferries was $900m.

Asked if he had confidence in KiwiRail's board, Peters said: "I'll give you an answer when I've talked to them."

Peters noted he would be asking how KiwiRail messed up the iRex project.

Willis ruled out buying second-hand ferries, noting that many owners were contacted and no ferries were open for purchase.

She committed that "no matter what, we will be procuring two ferries" at a lower cost than iRex.

Willis said New Zealanders should be reassured that the country's railway networks was in good hands with Peters as the minister responsible.

The Government wouldn't pre-select what shipyard would be building the new ferries, Willis said.

She wouldn't disclose how much the Government's financial envelope was. Procurement would begin in March.

"That would be unwise," Willis said when asked if the public deserved to know how much the Government was estimating it would pay. She said it could compromise the Government's negotiations

Asked if the current ferries were suitable for the coming years, Willis said they could be maintained to be safely viable to the end of the decade. Willis said she had expressed to KiwiRail that safety was a key priority, given the several issues the ferries had encountered.

Willis cited advice from her ministerial advisory group that said medium-sized ferries would be suitable.

Willis confirmed there was a chance for the ferries to be fully rail-enabled, also known as roll-on, roll-off. 

She said options would be considered between now and March next year.

"We are open to exploring a range of options."