The government’s plan to test all students before they leave university was thrown into question on Sunday after the UK’s largest academic union raised “grave concerns” about the accuracy of the Covid-19 tests being used and warned that this week’s mass evacuation of students was a “recipe for chaos”. The University and College Union (UCU) also said that many students have already returned home without being tested and it expects some will decline to take the voluntary test, because they do not wish to self-isolate in their halls of residence. The union also stressed that not all universities have agreed to participate in the government’s mass asymptomatic testing scheme, which begins on Monday. The Department for Health and Social Care confirmed on Saturday that only 130 higher education institutions in the UK - 79% - have expressed an interest in taking part in the testing scheme. It is understood that at least 35 institutions are either carrying out their own testing regime, or not testing students at all. The government is supplying universities with lateral flow tests, which can be self-administered by asymptomatic students and do not require laboratory processing, offering “rapid results within an hour”. However, these tests have been criticised by experts in the British Medical Journal as an “unevaluated, under designed and costly mess”, with particular concerns raised over infected people receiving false negative results. Government-backed assessments carried out by Public Health England’s Porton Down laboratory and the University of Oxford suggests the tests may miss as many as half of Covid-19 cases, depending on who is using them, and that they are unsuitable for a “test and release” strategy that will allow asymptomatic students to go home. The study found that the sensitivity of the test dropped from 79% to 58% when it was used by self-trained members of the public as opposed to laboratory scientists. In its guidance to students returning home, updated last Tuesday, the Department for Education admitted that the test would not detect all positive cases. “The flaws in government plans for mass testing are a recipe for chaos that risk spreading the virus – the very thing they are designed to prevent,” said Jo Grady, UCU general secretary. “We have grave concerns over how this programme will be carried out, particularly the risk of students being told – incorrectly – they do not have Covid, then relying on their test result to travel home and spend Christmas with vulnerable relatives. There are also questions to answer on whether staff responsible for administering the tests have received the medical training to evaluate them properly.” Students are being urged to take two tests, three days apart. All tests need to be completed by the end of term (9 December) and students who test positive will be expected to immediately self-isolate at their university accommodation for 10 days, along with contacts and members of their household. Those who test negative are being advised to return home “as soon as possible” after receiving their result: Exeter University, for example, is advising students to “aim to leave within 24 hours”. The student “travel window” – the period in which all students are being asked to travel home by the government – will run from 3 to 9 December, meaning that mass testing and the travel window will finish on the same day. UCU said many students do not yet know which days they will receive their tests, and that testing hundreds of thousands of people in such a small timeframe – while following social distancing rules – would be “extremely challenging”. ‘The government chose not to listen to us when we warned that the mass movement of students in September risked the nation’s safety, and it has ignored requests from its scientists, and UCU, to move learning online to help control the virus,” said Grady. “By choosing to continue with in-person learning until the last minute, ministers are gambling with the safety of staff, students and the nation, betting everything on an untested testing programme.” Alistair Jarvis, the chief executive of Universities UK, said: “Over the past few weeks university staff across the UK have worked with the government at considerable pace to develop and roll out enhanced asymptomatic testing for students, as part of the next phase of pilots for the largest network of diagnostic testing facilities in British history. As well as ensuring students can return home this Christmas, these pilots will enable vital lessons to be learned on the nationwide scaling up of asymptomatic testing that other industries and society as a whole will substantially benefit from.” A government spokesperson said: “We have set out tailored guidance to universities designed by public health professionals to enable students to return home for the Christmas holidays while minimising the risk of transmission. “The tests are safe, simple to use and do not require medically trained staff to administer them. Just like the tests available across our regional test sites, individuals will be asked to self-swab under guidance from trained staff.”