The government appears to have abandoned its “data not dates” principle, an expert advising its coronavirus response has warned, adding that its reluctance to delay unlocking was leading to “contradictory” messaging. Prof Stephen Reicher, a psychologist on the Scientific Pandemic Insights Group on Behaviours, joined scientists warning against the final lifting of restrictions on 21 June as cases passed 4,000 for the first time since late March on Friday. Reicher said the government had invested “so much political capital” in particular dates that it has become difficult to diverge from them if the data suggests it is necessary. He told BBC Radio 4’s Today programme: “I think we are in a pickle of the government’s own making at the moment. I think the reason for that is it has departed from its own mantra of ‘data not dates’. Very quickly ‘data not dates’ became ‘dates not data’.” The behavioural psychologist’s remarks come as the variant first detected in India spreads rapidly in hotspots across the UK. Cases of the variant of concern, known as B.1.617.2, have doubled over the last week, with up to three-quarters of new cases now thought to be caused by the variant. Reicher said: “The data we are seeing at the moment suggests we have a problem. We don’t know how big the problem is – it might be bad, it might be very bad, we will learn in the next week or two. “But the problem for the government is on the one hand it can’t delay what it has been promising for so long, but on the other hand it is aware of the dangers of so doing.” He said this unwillingness to postpone the relaxation of restrictions was leading the government to behave in a “contradictory” manner which is “undermining” its response – for instance, telling people they are allowed to travel internationally but are advised not to. “That contradiction, that sense of confusion, I think is undermining the response,” Reicher said. Prof Anthony Harnden, deputy chair of the Joint Committee on Vaccination and Immunisation, also advised erring on the side of caution as England looks toward 21 June. Harnden told BBC Breakfast there was a need to watch the spread of the variant first detected in India “very carefully” over the next one or two weeks. Harnden said: “Even if we do un-lockdown, if you are in a vulnerable position, particularly if you’ve not been vaccinated, you do need to carry on being cautious. “I think we’ve all got used to living within boundaries at the moment and I think it’s not an ‘all or none’, I think it will be a gradual process, even if the June 21 date goes ahead.” According to a report in the Times, ministers are considering continuing to advise remote working and the use of face masks after 21 June under plans to prioritise the end of social distancing. The end of distancing restrictions such as the 1-metre rule is considered vital for the recovery of the hospitality sector. On Friday, Prof Christina Pagel, a member of Independent Sage, argued that the final stage of unlocking should be delayed for two months “until a much higher proportion of people are vaccinated with both doses”, as one vaccine shot provides just 33% protection against B.1.617.2. So far, about 46% of UK adults have had both doses.