Dr Kelvin Ward has authored a petition asking the Government to raise the alert level to the highest possible. Photo: Supplied

Almost 3,000 people, including front-line health workers, are petitioning the Government to activate Covid-19 Alert Level Four immediately.

The petition's author, Dr Kelvin Ward, said raising the alert to the highest possible level was the only way for New Zealand to ensure it survives the virus with minimal impact.

As of 3pm, 2,900 had signed the petition calling for:

• Quarantine, not self-isolation, of all Covid-19 positive patients

• Extensive testing and contact tracing

• Self-isolation of all asymptomatic contacts

• Mandatory social lockdown

"If we want to prevent this epidemic becoming exponential, we have to take some drastic measures," Ward said.

Bloomfield this afternoon said the alert level was staying at 2 as there was still no evidence of community outbreak, though two possible cases were still being investigated.

An alert system is now in place for Covid-19 that can apply to the whole country, or to certain places or towns. Photo: Supplied

Alert level two means Covid-19 is "contained but risk of community transmission growing" and human contact must be further reduced - over-70s have been told to stay at home and everyone needs to limit domestic travel.

Ward, who is an urgent care physician, handed the Change.org petition to Bloomfield outside the Ministry of Health in Wellington this afternoon.

He said a wide-range of health professionals had signed the petition, including urgent care physicians, intensive care specialists, surgeons, nurses and pharmacists.

Raising the alert level to four would mean full lockdown of all non-essential businesses, rationing supplies, severe travel restrictions and major reprioritisation of healthcare facilities. Supermarkets will stay open regardless of the alert level.

Ward said community transmission was almost inevitable but New Zealand could limit it by activating alert level four.

"We know that there is a burden of disease in the community which hasn't been detected and we will not know that burden until days, or weeks, later."

Ward said there was a lot of evidence voluntary self-isolation didn't work and referred to the reports of tourists flouting the rules after coming to New Zealand.

"All it takes is one contact for it to potentially spread widely in just a few weeks.