Growing evidence of a link between air pollution and the impact of coronavirus means the government has a legal obligation to urgently review its air quality strategy, according to lawyers. In a letter to ministers, the lawyers argue that refusing to order a review would breach UK law, the precautionary principle and the European convention on human rights. Dirty air is estimated to cause 40,000 early deaths a year in the UK, and evidence is mounting that it is linked to increased Covid-19 infection rates and death rates. The lawyers, acting for Mums for Lungs and the Good Law Project, say this potential risk to life means ministers must act even if the evidence is not yet conclusive. The letter adds to pressure on the government from 90 parliamentarians who on Friday backed action on air pollution to help avoid a second coronavirus peak. Meanwhile, a new air pollution inquiry by MPs on the environment, food and rural affairs select committee will examine delays in the rollout of clean air zones in cities as a result of the pandemic. The failure to consider air pollution as a factor in the higher rates of coronavirus deaths among minority ethnic groups was recently called “astonishing” and “wholly irresponsible” by critics of a Public Health England review. Jolyon Maugham, the director of the Good Law Project, said: “When there is a risk of harm to human life, the government must take measures to alleviate that risk. With evidence piling up that links dirty air with cases of Covid-19, it is the government’s legal duty to conduct an urgent review. The government says they are listening to science. They must prove it.” Jemima Hartshorn, from the campaign group Mums for Lungs, said: “Air pollution is linked to cancer, respiratory illnesses, stunted lung growth, diabetes, cardiac diseases, strokes and many other diseases. In the midst of a respiratory pandemic, the government has to finally take the necessary action to ensure clean air for all.” The letter to the environment secretary, George Eustice, was sent by Hausfeld law firm, which is acting pro bono. “The mounting evidence [linking Covid-19 and pollution] renders wholly out of date the [government’s] previous assessments of the impact of poor air quality on human health,” the lawyers said. “Whilst this firm and our clients are sympathetic to the pressures facing government at this time, these matters are necessarily urgent in light of the likelihood of further ‘waves’ of the Covid-19 pandemic,” they said. “The longer the government delays this review, the longer this generation and the next will suffer from the impacts of Covid-19.” The letter notes that in May Prof Jonathan Van-Tam, the deputy chief medical officer for England, said the link between air pollution and coronavirus was “entirely plausible”, and that the transport secretary, Grant Shapps, said dirty air “remains a hidden killer”. It also notes that the health minister Lord Bethell has acknowledged evidence that inhaling pollution particles might “increase the spread or severity of Covid-19”. The lawyers have asked Eustice to commit to a review by 23 June and publish it within three months. If the government refuses, Mums for Lungs and the Good Law Project will consider further legal action. A spokesman for the Department for Environment, Food and Rural Affairs said: “We remain committed to being a world leader in tackling air pollution. As we rebuild our economy in response to the coronavirus pandemic, we will continue to shape a cleaner, greener and more resilient society.” Neil Parish, the chair of the environment select committee, said: “Even before the coronavirus pandemic, air pollution was vastly overlooked. The pandemic is threatening to push back some of the crucial work planned for addressing poor air quality, when it is clear that it should instead be a once-in-a-lifetime catalyst for action.” Geraint Davies, the chair of the all-party parliamentary group on air pollution, said: “It is vitally important that the prime minister acts immediately on the emerging science [linking pollution and coronavirus] and on our wide-ranging proposals backed by scientists, businesses, local authorities and 90 parliamentarians.” Davies said Eustice had agreed to meet to discuss the issues. The Hausfeld letter to Eustice is also backed by the Students for Global Health group. Its director, Harpreet Kaur, said: “A green recovery is vital to tackling the hidden crisis of air pollution. It is important we move on this quickly to ensure a healthy environment for current and future generations.”