A confidential Government plan for managing the coronavirus lockdown has warned that crisis measures could remain in place for a long time. 

Stuff obtained the details from the April 1 copy of the Government's National Action Plan, from the National Crisis Management Centre (NCMC).

The plan said there was a "likelihood that the response will have to be sustained over a protracted period before a transition to recovery can be considered".

It did not go into detail about what the Government would want to see before the country's Level 4 lockdown ended. Nor did it specify what a "protracted period" means.

Eventually, it said, there would be a discussion with an official, called a "recovery manager", who would identify "when/if [the country] can begin transition from response to recovery", but did not detail what that discussion would be or when it needed to be held. 

A spokesman for the Government said "action plans are standard operational documents produced during emergency responses that describe how response objectives will be achieved.

"They set out what the overall mission is, what the objectives are, and the high level approach and tasks that will be undertaken to achieve those objectives.

"This operational document ensures everyone involved with delivering the response is on the same page and is clear about what they need to do."

It's understood the document was circulated around top officials in central and local government.

The Government was understood to be looking at ways to exit the Level 4 lockdown, including isolating regions where the virus persists, but that work was at an early stage and hadn't been made public

The leaked plan warned that protecting the capacity of the health system was a top priority for the country during the coming weeks.

It said that while "New Zealand has an excellent health system" there was "a limit to the services that are able to be provided, which may well be tested during an outbreak of a Covid-19 with pandemic potential".

That would vary region-to-region, where some areas "the health system already reaches capacity at peak times".

A Covid-19 outbreak would put particular strain on acute care, intensive care nursing, emergency medicine and ambulance services as well as specialist equipment.

Local GPs would also feel the strain, as services at hospitals changed to meet the demands of the outbreak, pushing healthcare back to community GPs. 

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It warned that while the Level 4 alert — effectively a national lockdown — had been set out for an initial four weeks, that would be "monitored and reviewed" which could mean the level 4 period being "amended".

Director-General of Health Ashley Bloomfield said on Thursday the Government didn't have a "plan b" if the lockdown failed, saying a situation allowing mass death was untenable. It would stay in the "stamp it out" phase as long as necessary. 

Over recent days there has been some confusion over whether the Government planned to manage the impact of Covid-19 until a vaccine was developed, allowing for sporadic outbreaks and rolling peaks, or whether it wanted to eliminate the disease completely. 

A document from the All of Government Response, published this week, said the strategy had shifted. That document said the Government was responding to a shift in Covid-19 strategy from a "mitigation or 'flatten the curve' approach to the current stamp it out and elimination strategy".

That appeared to confirm the advice of experts such as Sir David Skegg of the University of Otago who briefed Parliament's Epidemic Response Committee this week, saying it was necessary to completely stamp out the virus over the coming weeks. 

Skegg was himself confused by some of Government's strategy around eliminating the virus.

"Some statements have implied a goal of eliminating the virus, while others imply suppression, even mitigation," Skegg told the committee on Tuesday.

The suppression strategy still included multiple outbreaks throughout the year, with the main goal still being to ensure hospitals were not overwhelmed. 

The plan delved into some detail about the Government's powers and flags areas the Government was watching closely, including demand for goods, which could result in "strategies to supplement likely shortfalls".

Meanwhile, there have been calls for the Government to start planning to exit level 4 alert and to plan for ways to mitigate the exceptional economic damage, which some expect will be so severe that it pushes the unemployment rate to double digits.

On Wednesday, economist Shamubeel Eaqub told the select committee that businesses he advised were asking what would indicate an end to the lockdown.

"What are the triggers we should be looking for? What are the triggers that are going to end it, or extend it?" he said. 

"If it's not in four weeks time, then I want to hear from Grant Robertson what are the additional things you're going to do, or not, so that we know".

But the emergency plan was relatively silent on plans to exit the lockdown.

Of the plan's 32 pages, roughly a quarter of a page is dedicated to "recovery" from the crisis.

These points are fairly vague. They include things like establishing a team to support recovery, identifying "immediate, medium, and long term consequences to New Zealand, including identifying information gaps" and trying to "assess the level of intervention government will need to have in recovery".