Mr Coleman told The AM Show that the Manukau DHB didn't raise the alarm before a select committee in February, and he knew "absolutely nothing" about the issues.

"I spoke to the DHB regularly, I visited it regularly - was not told anything of the problems," he says.

"We had the DHB before the select committee six weeks ago, read it thoroughly, no mention of these problems."

Marama Davidson, new co-leader of the Greens, said she gave birth at Middlemore and its awful state is absolutely National's fault.

I can't act on a leaky building if I'm not told about it.

"When the previous National Government were focused so hard on a surplus at all costs, yeah they're probably going to ignore and not proactively make sure that the hospitals are doing okay," she told The AM Show previously.

"It's not good enough that Simon Bridges has just finished telling you 'we didn't know' and that's his fob-off. That's not good enough at all. They needed to ensure they knew what was going on."

However Mr Coleman argues that if the problems weren’t raised, he couldn’t possibly have fixed it.

"I can't act on a leaky building if I'm not told about it," he said.

"This is news to senior clinicians out at Middlemore. Even Dr David Galler, he's writing on the Spinoff saying this was a big revelation to him."

Mr Coleman argued that the new Government is making things out to be as bad as possible because Labour has "massively overpromised" and have realised it can't deliver on everything.

"Because they know they have greatly overpromised they're trying to trash our record on everything," he says.

"That's what this is all about."

Prime Minister Jacinda Ardern dampened down expectations of the upcoming Budget, explaining the underfunding in "almost every portfolio" was much worse than she thought.

"We thought it would be bad. We didn't know it would be this bad," Ms Ardern said at her weekly post-Cabinet press conference.

"We will not be able to address nine years of neglect in one Budget."

Watch the full interview with Jonathan Coleman above.

The AM Show with Duncan Garner, Amanda Gillies and Mark Richardson, weekdays 6-9am on RadioLIVE and streaming live to the rova app on Android and iPhone.