The “rapid turnaround” coronavirus tests the prime minister announced on Saturday are not approved for the public to interpret themselves without an expert’s help and so will not provide results in the promised 15 minutes, the Guardian has learned. Boris Johnson’s briefing about this week’s national lockdown in England included the promise of a mass rollout of “tests that you can use yourself to tell whether or not you are infectious and get the result within 10 to 15 minutes”, which would be made available at universities and across whole cities. He said the army would be deployed to roll out the “many millions of cheap, reliable and above all rapid turnaround tests” everywhere they were needed. Three of these rapid antigen tests, called lateral flow tests, have passed an assessment by Porton Down with Oxford University. The government has bought one of them. The health secretary, Matt Hancock, announced the government had signed a deal for 20 million, from the company Innova Tried and Tested, on 19 October. But the Innova tests are not for people without symptoms, such as university students or people wanting to get on a plane or go to the theatre. They are designed for people who already have Covid symptoms. And the devices, which look like a pregnancy test, are intended to be read by a healthcare professional. The company is clear about their limitations on the instructions for use, which can be found on its website. The tests analyse throat and nose swabs “from individuals who are suspected of Covid-19 by their healthcare provider, within the first five days of the onset of symptoms”. The test is designed for use by trained lab and healthcare staff, it says. Johnson hopes the tests will help show the way out of the pandemic. They will be deployed in a wide range of situations, he said, “from helping women to have their partners with them in labour wards when they’re giving birth, to testing whole towns and even whole cities. “The army has been brought in to work on the logistics and the programme will begin in a matter of days, working with local communities, local government, public health directors and organisations of all kinds to help people discover whether or not they are infectious, and then immediately to get them to self-isolate and to stop the spread.” Prof Jon Deeks from Birmingham University and a member of a working group of the Royal Statistical Society, which is looking at coronavirus tests, said they were not ready for this type of use. “At the moment, if you were bought this test, you would not be using it for this purpose,” he told the Guardian. Lateral flow tests are now being offered to students at two universities – Durham and De Montfort – in a pilot study. Deeks questioned whether those involved had the right information. “There are real issues in what people are being told in these studies,” he said. There was no transparency around the assessment of the lateral flow tests, he said. The announcement that the three tests had passed did not explain how they were assessed or how well they performed. While everyone agrees that lateral flow tests, which could use either swab samples from the nose and mouth or saliva, have huge promise, Deeks said the technology at the moment appeared to struggle to register low levels of virus. They may pick up people who are infected and have high virus levels and may have symptoms, but they tend to miss people who are asymptomatic, as many young and fit people are. A second test approved by Porton Down, from the Korean company SD Biosensor, has been validated by the World Health Organization and a package of support has been agreed to supply low- and middle-income countries that do not have access to PCR lab testing. However, these tests are also to be read by a healthcare professional. Mass testing was part of the government’s controversial Moonshot plans. Last week the Guardian revealed that local health leaders had been asked to sign up to testing 10% of their populations every week using lateral flow tests, following the announcement of the deal with Innova. In a leaked letter, Alex Cooper, the director of rapid testing at NHS test and trace, said the ambition was “to make this technology available for local areas to roll out at pace”, adding that the programme would go nationwide “as quickly as possible”. Labour has called for frontline workers and vulnerable people living in coronavirus hotspots to be tested every week. NHS staff and those working in education, transport, retail and hospitality, as well as at-risk groups in areas with high infections, should be given access to rapid saliva tests, the party said. It urged ministers to use the November lockdown to expand testing and fix contact tracing, saying that a plan to roll out strategic mass testing would provide a roadmap for containing the virus.