Downing Street leaned on Public Health England not to publish crucial data on the spread of the new Covid variant in schools, documents seen by the Observer have suggested. Scientists, union officials and teachers said that the lack of transparency was “deeply worrying”. The focus of their anger concerns the pre-print of a PHE report that included a page of data on the spread of the India Covid-19 variant in schools. But when the report was published on Thursday 13 May, the page had been removed. It was the only one that had been removed from the pre-print. Days later, the government went ahead with its decision to remove the mandate on face coverings in English schools. Evidence seen by the Observer suggests No 10 was directly involved in the decision not to publish it. The prime minister’s office acknowledged it was in correspondence with PHE officials about presentation of the data but vigorously denied this constituted “interference” or “pressure”. Data on the spread of the new variant in schools has still not been published, despite calls from union officials and scientists who say teachers and families are being put at risk. In hotspots such as Bolton, cases involving the variant are rising fastest among school-age children. Information seen by the Observer reveals that 164 cases of the new variant were linked to schools up to 12 May, or 13% of a total of 2,111 cases. Since then, the number of total cases of the new variant has risen to 3,424 cases, a rise of 160%. The number of cases now linked to schools is unknown. PHE will only say the data will be published “in due course”. It declined to comment on whether Downing Street has played a role in the decision. Minutes from the Sage advisory group meeting last week warn the new variants are “capable of generating a wave of infections bigger than previous waves”, and that the danger of “overreacting seems small compared to the potential benefit of delaying a third wave until more people are vaccinated”. Christina Pagel, professor of operational research at University College London, said the situation was very troubling. “It feels like bad news that we’re not being told. “There is a narrative that schools are safe but the data clearly shows this variant can and does spread in schools. Two weeks ago, the Singaporean health minister closed schools because of the risk of greater spread in children of this variant. “Parents, teachers and children just need this information in order to take steps to keep themselves and their communities safe. The new variant is the biggest threat to the roadmap according to Sage, but the data is just not coming out in a transparent and timely manner. I just feel like PHE is letting us down at a crucial time.” Deepti Gurdasani, at Queen Mary University, London, said: “We know from media reports there are many outbreaks of the so-called ‘India variant’ in schools but there’s no systematic data. In Bolton, it’s risen fastest in school-age children and it looks like schools are contributing to the rapid spread of the virus … and yet at this crucial moment, the government has gone ahead and lifted mitigations. It’s incredibly worrying. “This is a public health emergency and PHE is supposed to be an independent public health body. It is crucial that they have the public’s trust.” Jon Richards, head of education for Unison, said the union has repeatedly asked for this data for weeks. “We were told it would be in the report last Thursday but it wasn’t. We were then told it would be published this week but that report has simply not appeared. In the meantime, the government has gone and lifted the rule on face coverings.” A Downing Street spokesperson said: “Twice a week Public Health England publish a breakdown of the number of cases of each variant in the UK. Given public interest in variants of concern, we are looking at ways to publish cases transmitted in different settings in a robust and clear way. PHE will publish this data in due course.”