Ministers meet at 10.30am for an extended Cabinet meeting to discuss the move. Just over six hours later, Ms Ardern will front media with the decision, at 4pm.
If Cabinet decides the country is ready to come out of Level 3, New Zealand could be moving to Alert Level 2 as early as Wednesday.
And if Level 2 is green-lighted, one of the country’s top epidemiology experts says the Government should consider making the wearing of masks on public transport compulsory.
"This would give us another line of defence," Otago University epidemiologist Prof Michael Baker said.
Ministers, some physically in the Cabinet meeting room and others joining via video link, will weigh up advice from the Health Ministry and other key agencies before making the final call.
It comes after New Zealand effectively ground to a halt almost six weeks ago, when the country went into lockdown at Alert Level 4.
The economic impact of the lockdown has been stark. Recently released Treasury documents reveal officials expect 300,000 people to be out of work by September.
Businesses, the Opposition and even the Deputy Prime Minister Winston Peters have all lobbied for the Government to move as fast as possible into the less restrictive Level 2.
National leader Simon Bridges said that tens of thousands of jobs have already been lost.
"This has gone on too long. It’s time to put more trust in everyday New Zealanders and get working again."
But Ms Ardern has been clear New Zealand would only move to Level 2 when it was safe to do so.
"We think of ourselves as halfway down Everest. I think it is clear that no-one wants to hike back up that peak," she said last week.
From a health perspective, Director-general of health Ashley Bloomfield has always said his advice would be based on a sustained period of low new cases, low to no community transmission and an ironclad understanding of where each case came from.
Dr Bloomfield will personally be briefing ministers today on his recommendation.
This comes after a week of consistently low new cases of Covid-19.
There were just 11 new cases in the last seven days and for two of those days there were no new cases.
Yesterday, there were just two new cases and no further Covid-19-related deaths. The Ministry of Health also revealed that 92% of all Covid-19 cases have now recovered.
One option for Ms Ardern and her Cabinet is the phasing into Level 2, something she has spoken about
publicly.
"Moving into Level 2 is a large step. We would rather start that journey than to wait back in Level 3 longer than we need to, but it may be that we get advice that the higher risk elements of Level 2 may need a little more time," she said last week.
This would be a similar approach to that of the Australian Government. Ms Ardern and Australia’s Prime Minister Scott Morrison have been sharing notes as both countries battle the pandemic.
Speaking to the Herald, Prof Baker supported this approach.
"Thinking logically, you might begin with the most controlled environments, like workplaces and schools, where risk can be minimised."
Then, once officials are sure Level 2 was showing signs of success, the Government could loosen restrictions on places like bars and nightclubs, Prof Baker said.
But he said the Cabinet has a "tough balancing act" to consider when making its decision today.
It needed to weigh up public health against the potential economic impact of extending Level 3, he added.
But going to Level 2 would be a big jump, given the social restrictions would be loosened considerably, compared with the other alert levels, he said.
In Level 2, shops will open, people can go to bars and cafes, domestic travel is allowed and people will again be allowed to gather at events of fewer than 100 people.
Prof Baker said this was where the risk of a second wave was most pronounced.
One way to mitigate this issue would be for the Cabinet to tighten rules concerning masks.
Prof Baker said the Government should consider making it a requirement that people wear masks on public transport and planes.
The Cabinet does not vote, per se, on decisions. Rather, ministers come to an agreement regarding a decision, after hearing advice from top officials, such as Dr Bloomfield.