Leader of the Opposition Simon Bridges says the Government has enough money to build two new hospitals, let alone fix the problems at Middlemore Hospital.

Bridges conceded today that the situation at Middlemore was "not good enough" and said former Health Minister Jonathan Coleman should have been told about its dire state, which includes mould and asbestos in the walls and unreliable power sources.

"In relation to Middlemore, there is nothing about that that is good enough," he told RNZ National.

"I am not going to come here and sugar coat the situation there."

Coleman, who is resigning from Parliament, had told Bridges that he had not been advised about Middlemore's problems.

"Should he have known? Yeah. And it should be interesting to see exactly what has happened there."

Bridges did not go as far as saying it was a failure of ministerial oversight.

He did, however, say Coleman should have fronted up and answered questions about the issue.

Coleman hung up on RNZ when he was asked about Middlemore two weeks ago, saying he had been expecting an exit interview and not questions about his previous portfolio.

"Should my Members of Parliament come on [the show] and answer your questions? Yes they should," Bridges said.

Coleman said today that if he had been informed about leaky or mouldy buildings at the hospital while in government he would have immediately "put it to the top of my list".

Counties Manukau District Health Board executives had their annual review at Parliament in February, and no mention was made of mouldy or leaky buildings, he said. Reference was made to patient numbers and demands on infrastructure but there had been no specific discussion of the state of any buildings.

Bridges turned the argument on to the Labour-led Government, saying that it could easily cover the costs of repairs at Middlemore but was prioritising other areas.

"Frankly what I see from a Government here is a sense that they've got a huge raft of promises they cannot keep, taxes they want to impose, so they are looking for ways in the leadup to the Budget – which they are clearly worried about – to get into these issues.

"They've got surpluses. They make their choices. They've decided $2.8 billion for free [tertiary] fees is the right way to go.

"Well that's two fully furnished Dunedin hospitals. They can deal with these issues."

This afternoon, Coleman spoke further about the issues with Middlemore Hospital, taking to social media this afternoon to say if the Counties Manukau DHB had known the full extent of the issue, it should have been "screaming it from the rooftops" and it was "just not credible" to say he should have known.

Coleman has largely stayed quiet on the issue till now, but today wrote that he had been reviewing "a couple of very pertinent documents".

They include the transcript of the Counties Manukau DHB appearance before the health select committee in February, in which no mention was made of the problem with buildings.

"Surely if the building problems were known about the DHB chair and acting CEO would have been screaming it from the rooftops at select committee?" he wrote.

"Did they know about the problems? If they did why didn't they raise it at the Health Select Committee? And if they didn't know about it, how could a minister know?"

A second document from the Auditor General in 2016 also claimed that buildings at Counties Manukau had a "through life" of 11 per cent, meaning they had 89 per cent of their useful lives remaining, he said.

"That's the second lowest of all DHBs. Hardly a red flag for imminent buildings problems at Middlemore."

But former DHB chairwoman Dr Lee Mathias quickly weighed in with a response, saying there was "nothing dodgy or secret about the state of buildings at Middlemore".

She said the problems were all well known and had been regularly reported.

"Ministers, including Coleman, signed off remedial work eg the complete rebuild of the Mental Health facility in Minister Coleman's case."

Mathias said the 11 per cent through-life of the buildings was also misleading as it included the brand new $298m Clinical Services block.

The Herald has asked the DHB for comment.