There is confidence from a Labour Minister that the Covid-19 vaccine roll-out will be successful.

Auditor-General John Ryan says there needs to be a significant scale up for the Government to hit its vaccine targets.

Stuart Nash told Mike Hosking the roll-out will be done incredibly professionally.

He says the Pfizer vaccine has been proven to be the best vaccine with the highest efficacy.

"We have got enough Pfizer vaccine to immunise and vaccinate the whole country."

However, National MP Mark Mitchell claims we're falling behind the world and will lose key opportunities.

"We're not going to be able to capitalise on the good response in the country we have had because we're going to be stuck here unvaccinated."

Meanwhile, Mitchell is throwing his support behind Judith Collins.

The National party leader's dipped in the latest poll to 5.6 percent support as preferred Prime Minister.

Observers have decided Waikato MP Tim van de Molen wasn't emphatic enough when asked whether Collins would still be leader in 2023.

He told reporters he doesn't have a crystal ball to predict whether that would be the case.

Mitchell told Mike Hosking van de Molen was in a media scrum, where three or four questions are often fired at the same time.

"At the end olf the day, it's quite simple that the caucus is 100 percent behind Judith, she is our leader and will be our leader heading into 2023, it's as simple as that."

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