How much of the Government's $8b health boost will be delivered in its first Budget?

The Government promised $8 billion in extra funding to the health sector over four years, but it's dampening expectations over how much of that will be seen in its first Budget.

Prime Minister Jacinda Ardern wouldn't say how much additional funding would go to health ahead of Budget Day on May 17, but said: "there's no doubt that we've been left with a bigger hole than we expected".

An example was that DHB deficits had blown out six-fold since September last year.

It follows the Government revealing an election promise to cut GP visit fees by $10 by July 1 2018, or to $8 per visit for Community Service Card holders, would instead be "phased in".

Ms Ardern said an announcement would be made about the policy in two weeks, but National leader Simon Bridges said the Government is simply "backtracking" and talking down its promise.

"You've got hard-working families who deserve to pay cheaper fees. We would have been able to prioritise that. These guys, because of all the promises they've made, broke their promise," he said.

"They don't need to be talking down GP visits. They should be able to meet those core promises on things that matter to families in New Zealand."

Ms Ardern says the Government will balance the GP visits promise with the need for "rebuilding, reinvesting in our hospital infrastructure, DHB deficits and making sure we've got a safe working environment for our health professionals".

A recent Treasury report estimated $14 billion would be needed within the next decade to replace or upgrade existing hospital assets, warning 19 percent of New Zealand hospitals are in a poor or very poor condition.

The New Zealand Nurses Organisation is in the process of holding a vote on strike action, after turning down a 2 percent pay rise offer from DHBs, and Ms Ardern believes their pay claim can be resolved.

Labour's other health election promises include establishing a National Cancer Agency, extending School Based Health Services to all secondary schools and introducing a mental health team pilot programme at eight sites across the country. It also has a number of health promises in coalition agreements to be met by 2020.

The Government will present Budget 2018 on May 17.

Newshub.