The director of a company importing rapid antigen tests wants the government to give businesses more of a role in providing supply.
InScience director Ann-Louise Anderson said it was having trouble filling customers' orders now the government had told suppliers it wanted priority.
"I've got back orders and forward orders sitting there, and people desperate to get their product for their continued surveillance programmes.
"These people have been doing surveillance programmes to try and protect their businesses and workers for at least a month now.
"They just can't continue, and I can't continue."
The government has 14 million rapid antigen tests arriving in a month but private businesses which also pre-ordered tests now face delays in getting their own tests.
Anderson questioned why the government had not stockpiled more tests earlier.
"I personally feel it's been a lack of planning because I've been able to get this product for the last two or three months if I'd wanted it.
"Why have they not been stockpiling it during that time?"
She said she had been able to get hundreds of thousands of tests.
Anderson said New Zealand could get more tests if authorities approved more brands. "These products that pass other jurisdictions are well tested. We would be able to get even more product".
Prime Minister Jacinda Ardern said approvals for tests made by different manufacturers were "being expedited".
"There's a huge variation - there are some real lemons out there. Some rapid antigen tests have accuracy as low as 30 percent.
"No-one wants to operate with rapid antigen tests that fail that often because it means not only will you have people diagnosed as having Covid who don't, there'll be people who do who will be out and about."
Tests would become available in pharmacies, GPs and community testing centres once there was a higher number of cases, she said.
Deputy Prime Minister Robertson told First Up there was a global shortage of the tests due to Omicron infections around the world, and the government's job was to help co-ordinate distribution to ensure critical supply chains kept going.
"We outlined the plan yesterday for how that will work. This is about what we called our return to work or test to work regime. That means that if somebody is a contact of someone with Omicron and they are in one of those critical industries. We can get them back to work using the rapid antigen tests."
"It's important that we use what we can in New Zealand to make sure that they're distributed to the places they're needed and that includes a number of private sector businesses."
Robertson said the tests would probably be distributed through pharmacies, GPs and the Ministry of Health.
Anderson said the government should realise importers and distributors had a part to play.
"[The government] should not try to be all things to all people.
"I'm still trying to figure out how they're going to get product to people that want it and need it.
"I don't know how they're going to do that and we have a part to play in it and we should be being worked worth, not just shut down."
She said most of the companies she supplies were vital businesses.
"They are the supply chain, the are the computer support people, they are the tradespeople."
Last night Anderson had managed to secure a new order of tests which should arrive mid-February. They were from a supplier she understood did not have an agreement with the government.
She said she was empathetic with the government "but they've just not worked with it well".