Winston Peters is slamming the National Party for announcing Government policy during the election campaign.

Prime Minister Bill English unveiled plans for a new $1.4 billion dollar hospital in Dunedin yesterday.

However, the Cabinet manual frowns on any Government announcements within three months of an election, as it can be seen as using public funds for campaigning.

Mr Peters says it shows they're desperate.

"This image that they're good economic managers is falling apart," he told Newshub.

"Have a good look at this case for example, and the many others they're now announcing in panic all over the place without the detail, and without the timelines, in the expectation that people will fall for it."

It's the latest faux pas from National on the campaign trail, after announcing its rail policy at a train station - a breach of Auckland Transport rules.

"It's a sure sign of opportunism and political desperation because they had a budget in May, no mention of it then," said Mr Peters.

"You've had all the questions about the level of hospital facilities in Dunedin. Then out of left-field, in the 11th hour, the National Party says it will build a new hospital."

Mr English said it was clear the city needed a brand new hospital.

"I know that this will be welcome news to people in Dunedin and also the wider southern area."

But Mr Peters suspects it may never be built.

"I think a lot of people will be asking the question: 'If it's so important, why did you leave it to the last minute?' Frankly, can we trust you, giving that you're panicking in the polls, to deliver this hospital after the election?"

Saturday's announcement was met with protests about the perceived lack of staffing and resources at the Southern DHB.

It's expected the hospital will be built under a public-private partnership model.

Newshub.