The Clutha mayor says as recently as two weeks ago the Otago Mayoral Forum was being "given the assurances that the promises would be kept" on the Dunedin Hospital project.

Clutha District Mayor Bryan Cadogan told Checkpoint he wanted the government to "show us the figures", saying the government should have known about costs at the time it promised to continue with the build during election campaigning last year.

But National ministers have laid the blame with Labour, saying the problems were hidden from them and from the public by the previous Labour-led government. Health Minister Shane Reti says the government remains committed to the hospital and has in fact "significantly increased funding for new Dunedin Hospital by hundreds of millions of dollars".

Prior to being elected, National campaigned on delivering Dunedin a hospital fit for purpose for generations, not just a patch-up job.

But a report commissioned by the government concluded the current hospital plans probably could not be delivered within the latest $1.8 billion budget from March, and last week ministers said the cost could balloon out to $3b.

Cutting back on what is in the plan, delays, or developing the old hospital site instead are now all on the table.

"The prime minister categorically made the statements at election time," Cadogan said. "He would have known then that it's an inflationary time - he also knew that he was going to do huge tax reliefs. ...You can't have your tax relief and eat it as well - if it doesn't balance, they're the government and they should have known it.

"$14b of tax reliefs, and then 'Duh, I haven't got the money'... we're getting told porkies."

An estimated 35,000 people marched through Dunedin in the weekend, opposing the government's announcements from last week.

But as recently as two weeks ago, a meeting of the region's mayors were updated about the hospital project by officials, and told that despite budget pressures it was all still go, Cadogan said.

He was now sceptical about the government's claims the project could now cost as much as $3 billion, and said other side-projects such as car parks had been heaped into the estimate, to make it appear larger than it actually would cost.

"I'm going to say right now that the figures that - this $3b - a nice round figure, but as it stands at the moment it has not been verified. We're just having to eat that figure as an excuse," he said.

"But what we're wanting to see is: Show us the figures, because we don't believe it is $3b.

"That's not the line we've been getting fed, and actually the lower South deserves better ... we don't believe the $3b will stand up to scrutiny."

"We're not getting the clear picture. It was categorically clear what was happening at election time, now it's mysterious. And for the lower South we're getting sick of it.

"And also there's the nagging doubt that if you add a car park in - well that adds on to the price, but a car park should be left to private enterprise. There's things that just aren't adding up.

"The Otago Mayoral Forum 15, 16 days ago was given the assurances that the promises would be kept - they were doing everything. There were certainly pressures for the finance, but it was still holding to the promises.

"We're livid. Definitely the messaging that we received was at a tangent to what ministers Reti and Bishop gave last week."

Cadogan accused the government of putting lives on the line to fund personal income tax reductions.

"We've got no choice... people will die here if the health facility is not up to scratch now, it won't be fit for purpose purpose in the future, and a building like this that's not fit for purpose ultimately correlates to deaths.

"So they're putting lives of the South on the line to save some money. The $14b tax relief ... we gave tax relief knowing that full well that there was going to be budget cuts on key infrastructure like this.

"It's just a basic expectation in New Zealand ... this has been almost two decades almost in the making - there's a reason it's there."

He wanted the government to put its money where its mouth was and deliver what it promised and what the southern regions needed.

"If that's what it costs - as long as it's an efficient build and all savings are looked at - then build the hospital that's needed.

"You can't give $14b in tax relief and then turn around and say 'Oh, I can't make the books balance, I'll build half a hospital' ... If you get one chance to build a hospital, don't build half a hospital."

The ministers respond:

RNZ put Cadogan's accusations to the government.

"Our government is committed to building a new hospital in Dunedin," Minister of Health Shane Reti said.

"In fact, our government has significantly increased funding for new Dunedin Hospital by hundreds of millions of dollars.

"Last week's was a difficult announcement, but it had to be made to ensure we can support other important builds across the hospital system. Hospitals in Nelson, Whangarei, Hawke's Bay, Palmerston North and Tauranga could be at risk if Dunedin continues to go so far over budget. That's not scaremongering - it's a financial reality.

"I want to assure the people of Dunedin and the south that Health New Zealand and ministers are fully committed to making sure we deliver long overdue solutions to their region's health infrastructure."

Minister for Infrastructure Chris Bishop talked about the project about-turn on Checkpoint on Friday, blaming Labour for hiding the true state of the project from National and the public.

His office on Monday reiterated his earlier comments about the new projections, in response to Cadogan's claims, repeating his statement that further detail about the cost blowout could not be given now due to commercial sensitivities.

What government said about the costs:

• Total appropriation $1.88b Recent cost estimates 
• several hundred million dollars over $1.88b
• Plus about $400m for a pathology lab, car parking, reuse/decommissioning of buildings
• All up, approaching $3 billion.

Open up the figures - Dunedin marchers

Cadogan was among those who marched in the weekend to protest the planned cuts.

He said claims that the money was not available for this project amounted to playing the different regions off against each other.

"The priorities are dead wrong when there's hospital cuts. Because I want Nelson and Whangārei and everyone else to have hospitals too - it's just a basic expectation for New Zealanders, but for some reasons we're getting played off against other towns - I want to see them get the health services they deserve," Cadogan said.

"All through the protest, everyone that I was talking to was asking 'please show us this $3b - don't just dismantle it without at least having the decency of the transparency of categorically showing us where that $3b is'.

"And actually New Zealand deserves better, the lower south deserves better, and actually something's up."

Main image (RNZ / Tess Brunton): A large proportion of Dunedin's population turned out on Saturday to protest news that the currently-underway Dunedin Hospital rebuild is being reconsidered.