Finance Minister Grant Robertson says lessons of hasty move up alert levels will be used in slide downwards

Finance Minister Grant Robertson says lessons from the hasty move into level four will be used to assess which businesses may be able to operate as the threat level of Covid-19 is lowered.

On Thursday Prime Minister Jacinda Ardern said that next week the Government would release detailed guidance of the impact of restrictions under level three, with Cabinet set to decide on April 20 whether to drop out of level four.

Ardern said employers should treat Covid-19 like a health and safety issue.

"Ask whether it's possible for your business to have social distancing? Can you build in contact tracing tools or mechanisms to keep track of your supply train and customers?"

New Zealand announced the threat level system, then moved to level four in less than a week, leading to lobbying and confusion about who was deemed to be an essential services.

The Warehouse wrongly told the NZX that it would be able to open, only to have to announce this was incorrect later.

Robertson told the Herald that the added time between now and April 20, as well as the lessons from the move up the alert levels, would help develop better guidance this time.

"I think we're going to learn a lot of lessons from the upward move we did, and one of those things is to give as much clarity in advance as possible, using [an] example-based approach," Robertson said.

"We've learned a lot about how people approach these issues. So I think we can use that [experience]. It doesn't mean it's failsafe, it doesn't mean it's 100 per cent, but I think it means we can develop that clarity."

The Finance Minister declined to say how much of the workforce may return to normal under a level 3 restriction, or say whether some industries such as hospitality may be prevented from opening.

"I think what we're trying to do is fit the principles and then work that through on a sector by sector basis. I'm not going to be able to answer that question today."

Nevertheless, he hoped significantly more activity would be able to take place.

"I'd like to think there's going to be a lot of activity possible in the economy, or a lot more activity possible in the economy than there is in level four."

Robertson said much of his Easter would be spent thrashing out guidance of what types of businesses could operate and what measures needed to be taken for them to do so.

"One of the conversations that has been taking place is [about] how can the construction industry work with physical distancing. Now in some ways it can but in other ways it's harder because of the need to have more than one person doing a particular job. So I know a lot of work's been going on to say, 'to what extent can we get the construction industry going under level three'," Robertson said.

"The second thing ... is can your business contact trace people who work there, people who go there, and people who are in your supply chain. That's becoming a very important thing for people to work out.

"Obviously we're still wanting to limit gatherings, mass gatherings of people, so that obviously is a physical distancing issue as well. It's also an operational issue for some businesses."

Robertson said businesses should also be contemplating a move back to level 2, which was in place before the lockdown, with requirements for social distancing but more scope for movement and gatherings.

"As long as long as things keep going well, we would hope not to be in level three for too long, and therefore level two, which has fewer restrictions," he said.

"What we're now doing is drawing detail of that, and trying to create guidance that as much as possible is clear on the basic principles you have to meet and has examples of what that means, so that businesses can plug themselves into it and say 'yeah, I can do that'.

• Covid19.govt.nz: The Government's official Covid-19 advisory website

"But as you can imagine it's a heavily consultative and heavily iterative piece of work and it'll be occupying a lot of my Easter."