A move to red if Omicron breaks out in New Zealand would "grind businesses to a halt", Tauranga Chamber of Commerce chief executive Matt Cowley says.
Prime Minister Jacinda Ardern announced the country would move to the strictest traffic light setting of the Covid-19 protection framework within 24-48 hours of the Omicron variant entering the community.
Ardern said the government knew, from other countries, it could take as little as 14 days for cases to grow from hundreds to thousands.
The Ministry of Health said in a statement that there was a possible case of Omicron in Palmerston North, believed to have been infectious from January 17.