Ending all Covid restrictions is premature and “not based on current evidence”, the British Medical Association has said, as experts warned dropping testing and self-isolation could lead to a surge in cases. Boris Johnson told MPs last week that he was preparing to lift the legal requirement in England to self-isolate on 24 February, a month earlier than originally planned, with a formal announcement expected on Monday. The prime minister is keen to claim victory for weathering the Omicron wave and placate lockdown-sceptics on his backbenches, who object to legal restrictions on daily life. But Dr Chaand Nagpaul, chair of the BMA council, said the decision was “not based on current evidence and is premature,” adding: “It clearly hasn’t been guided by data or done in consultation with the healthcare profession.” He said case rates remained exceptionally high, with the latest Office for National Statistics survey suggesting one in 20 people in England were infected last week. Ending self-isolation will form part of the government’s strategy for living with Covid, which is also expected to include the winding down of free mass testing for the virus. Ministers will hammer out the final details in discussions over the weekend. Rishi Sunak, the chancellor, has been pushing for a more rapid end to the costly testing regime, with Sajid Javid, the health secretary, keen to retain aspects of it for longer. The Guardian understands there are concerns within the NHS about some proposals under consideration, including dropping regular asymptomatic testing for healthcare workers, and restricting the use of the most effective PCR tests in hospitals to symptomatic patients, with others relying on cheaper lateral flow devices. Chris Hopson of NHS Providers said it was right for ministers to make decisions about the next steps, but Monday’s plan “can’t simply be a celebration about the removal of restrictions”. He said: “We have invested significant resource in creating effective testing and surveillance regimes that have been key parts of our defence in this highly uncertain environment. Whilst trust leaders recognise the ongoing cost of these regimes, they are clear that the government should err strongly on the side of caution before dismantling or scaling them back.” Experts on the government’s scientific pandemic influenza group on modelling operational subgroup, known as SPI-M-O, which feeds into Sage, warned that ending testing and isolation could lead to a return to rapid epidemic growth of the virus. In a document released on Friday the group note that estimates from a modelling team at the University of Warwick suggest that a combination of measures and behavioural change such as testing, self-isolation, mask wearing and increased home working are currently reducing transmission by approximately 20%-45%. “Warwick’s estimates are equivalent to there being the potential for transmission to increase by between around 25% and 80% if the population were to return to pre-pandemic behaviours and no mitigations,” the document says. “Warwick’s analysis indicates that, while behaviour change following the lifting of restrictions has previously been gradual, a sudden change, such as an end to testing and isolation, has the scope to lead to a return to rapid epidemic growth.” The group add that factors such as waning immunity, seasonality and the emergence of new variants could also affect transmission, either driving it up or down, adding that BA.2 – a close cousin of Omicron that is increasing in prevalence in the UK – may have a growth advantage over other forms of the variant. “If this were the case, it is possible that SPI-M-O’s medium-term projections may underestimate the short-term trajectory of hospitalisations,” the group wrote. A Department of Health and Social Care spokesperson said: “We continue to monitor the data closely and next week we will set out our plans on how we will live with Covid-19 in the long term.” Labour and trade unions are calling on the government to improve sick pay, to ensure that low-paid workers don’t feel forced to go into work while suffering from Covid-19, once the legal restrictions are lifted.