Prime Minister Jacinda Ardern will at 4pm front to the media as the Ministry of Health today admits undercounting the number of people hospitalised for Covid-19.

In a tweet, the Ministry said this has seen the number hospitalised since the start of the pandemic increase by over 5000 people, from 14,043 to 19,476.

The Ministry said it was due to a "coding issue".

Speaking after the Cabinet meeting today, Prime Minister is also expected to be asked about Covid-19 as case numbers start to rise - and ministers decide whether to continue with the current mask rules.

The Covid-19 Epidemic preparedness notice which gives the Government the power to implement Covid-19 restrictions and rules - such as mask mandates - is due to expire on October 20 unless it is renewed before then.

Cabinet had considered letting it lapse three months ago when it decided to drop the traffic light system, but opted to renew it then to allow it to continue to require masks in health settings. It is expected to decide today whether to renew it again - which requires the PM to state she is satisfied Covid-19 is "likely to continue to disrupt essential governmental and business activity in New Zealand significantly".

Earlier today, Ardern hit back at New Zealand First's leader Winston Peters' claims from the weekend's party conference saying "some of them are plain wrong".

"I'm wary - on some of the more extreme statements - just wary of, I guess, giving them any more headlines. Because some of them are just plain wrong," she told TVNZ's Breakfast show.

Ardern said she was otherwise happy to discuss things like the agricultural emissions proposal that had been put forward because NZ First ultimately voted for the Zero Carbon Act, which set a target to reduce emissions.

Ardern is also likely to be asked about ram raids, with new police data showing in August there were more than two a day.