Aucklanders headed to supermarkets in their droves last night, flooding into late-night outlets across the city ahead of the level three lockdown that comes into effect at midday.

Queues are expected again this morning as the city prepares for life under the restrictions designed to halt the spread of New Zealand's first community transmission of Covid-19 in over 100 days.

New World Victoria Park opened its doors to queues of at least sixty early bird shoppers this morning.

The first people in line had been there since 6 am.

For many, it was their usual weekly shopping day, but several had set their alarms to get in "before the rush".

New World management said there was no limit on shopping capacity at the moment, but at midday it would reduce to 188 including staff.

Despite pleas from Prime Minister Jacinda Ardern and Auckland mayor Phil Goff to remain calm, shoppers immediately headed to stores last night.

"Please do not rush to the supermarket tonight ... there is no reason to rush out and back any purchases this evening," Ardern said during last night's announcement.

Goff echoed the sentiment, calling for calm and patience as another level 3 lockdown looms over the city.

"I understand that people are probably feeling a little bit scared, a little angry and a little confused right now. None of us wanted to go back into a lockdown, but we always knew this was a very real possibility.

"I am urging Aucklanders to come together like we did last time to stamp out community transmission. Please remain calm, please do not panic buy and please follow the lockdown rules."

Many did not listen, despite the fact that supermarkets and pharmacies will remain open as essential services.

Countdown New Lynn was forced to close shortly before 10.30pm, an hour and a half early, after an influx of shoppers.

A witness told the Herald the line to the store stretched halfway down the New Lynn Mall, with dozens of shoppers inside stockpiling staples including rice, bread and pasta.

Supermarket staff were distributing masks to other staff to keep them safe, but the witness had only seen two customers wearing masks.

Simon Oosterman told Newstalk ZB the line of eager shoppers stretched 2km from the Countdown New Lynn supermarket.

"I counted over 200 people in the line, there are cars literally queuing up outside because there aren't enough car parks."

Oosterman had been standing outside the supermarket for the past half hour and the queue hadn't yet budged, he said.

Countdown Lynfield has also closed early, a customer said.

A Greenlane shopper told the Herald he abandoned the idea of shopping at the supermarket when he saw the queues snaking out the door.

"It was chaos. There was traffic blocking all of the roads leading to the supermarket, the parking lot was completely full and there were cars queued to get into the parking lot.

"There was already a queue snaking outside. I didn't think I'd even be able to get a park, let alone get the shopping done before the store closed."

Supermarkets shift back into lockdown

Last night, Kiri Hannifin, Countdown's general manager health & safety, said staff were well practised in what needed to be done in stores to keep team and customers safe.

"Over the next few hours, we'll be working to bring our level 3 measures into place in Auckland, and level 2 measures throughout the rest of the country. This will include physical distancing measures in our stores, limits on customer numbers, limits on some products, queue control and extra cleaning.

"We'd echo the Prime Minister's comments that there is no need at all for anyone to stock up - we have plenty of food and supplies for everyone and we want everyone to shop as they usually would and consider others."

Elsewhere, customers visiting 40 Foodstuffs stores - New World, Pak'nSave, Four Square - across the wider Auckland region can expect to see customer and team safety measures in place.

In a statement, Foodstuffs said 2-metre social distancing, restricted customer numbers in-store, one customer and one trolley, no bag packers at check out, no reusable bags to be bought into the store, increased sanitisation, hygiene and cleaning protocols throughout the supermarket including, on entry, at checkout and other high touch areas and social distancing signage and posters advising of customer requirements to be introduced.

Outside of Auckland, customers can expect to see increased sanitation and safety measures at their local supermarket too.

"These measures will be in place, initially from midday Wednesday 12 August until midnight Friday 14 August - but this may be extended depending on the advice received from Government over the coming days," the Foodstuffs statement said.

"While we truly hoped it wouldn't happen, as a business we just had to plan that another outbreak could occur, and the teams have been prepared for some time should we need to reinstate previous Alert Level protocols.

"Foodstuffs has good stocks of PPE and hand sanitiser, and our teams are familiar with what is required to keep both themselves and our customers safe from Covid-19.

"We would like to reassure customers that, just like before, our supply chain is robust. We are working hard to make sure all the grocery items New Zealand households might need are on the shelf and readily available."