Hundreds of doctors have urged politicians to stand firm on initiatives to tackle air pollution, warning that they see its “devastating health consequences” in patients on a daily basis. Air pollution is the single largest environmental risk to public health, linked to between 28,000 and 36,000 UK deaths a year. The estimated cost to the NHS and social care of air pollutants is estimated to be £1.6bn between 2017 and 2025. Keir Starmer and other senior Labour figures have prompted alarm among health professionals after they called on the London mayor, Sadiq Khan, to reflect on the expansion of the capital’s ultra-low emission zone (Ulez) after the Uxbridge byelection defeat. The Conservative candidate for London’s mayoral election next year, Susan Hall, has pledged to “stop the Ulez expansion on day one” if elected. In a letter to Starmer and Khan seen by the Guardian, more than 400 doctors begged them not to be intimidated into watering down city-wide schemes aimed at cutting air pollution levels in order to chase votes from a “vocal minority”. The letter, signed by GPs, respiratory consultants, radiologists, chest physicians, paediatricians and public health doctors, said: “As health professionals who see the devastating health consequences of air pollution daily, we implore you to stand firm in your commitment to expand Ulez to benefit the people of outer London. “Air pollution affects every one of us from before we are born into old age. It not only causes respiratory conditions such as asthma, but also heart attacks, heart arrhythmias, strokes, child developmental disorders, lung cancer and dementia. “Ulez works. It has already saved lives and prevented many illnesses and hospital admissions.” The doctors said they recognised that less affluent people would struggle to either change their vehicle or pay the Ulez charge, calling for it to be expanded in tandem with “a commitment to a much more affordable, frequent and reliable public transport system”. They wrote: “You cannot allow a vocal minority, who ignore the science to suit their own ends, to intimidate you into watering down or pausing the scheme. Doing so may buy you some votes from those people, but at what cost?” Long-term exposure to air pollution is associated with chronic conditions such as heart disease, asthma and lung cancer, reducing life expectancy, the doctors said. Short-term exposure to high pollution levels can cause coughing, wheezing and asthma attacks, and is leading to increased hospital and GP attendances, they added. Dr Jackie Applebee, a London GP and organiser of the letter, said: “Patients move to London from places with cleaner air and tell me that they experience coughs they never had before and that they can’t exercise for so long without getting short of breath. They usually think that they’ve lost fitness but I believe that they are experiencing the effects of air pollution.” Dr Laura Jane Smith, a consultant in respiratory medicine at King’s College hospital in London and a co-organiser of the letter, said schemes such as Ulez were essential to tackling ill health. “My patients ask me why their breathing is so bad when they do all the right things – stop smoking, exercise and eat well. The answer is air pollution. “It’s robbing them of their health and shortening their lives. Large-scale interventions to reduce air pollution levels such as extending Ulez are long overdue.” Dr Emma Radcliffe, a GP in London and the third co-organiser of the letter, said she was seeing patients with heart disease presenting with chest pain, and people with asthma with breathing problems. “I know from all the data that my patients have worse health because of the toxic air they breathe,” she said. “Clean air is one of the building blocks of health and that’s why I think the Ulez expansion is important.” Despite the clear effects on health, air pollution has been formally listed as a cause of death in just a single case, that of nine-year-old Ella Kissi-Debrah, who died in 2013 after an acute asthma attack. A coroner ruled in 2020 that she had died of asthma “contributed to by exposure to excessive air pollution”. “We implore you not to ignore the needs of the majority, particularly those in the most deprived areas,” the doctors wrote. “Ella Kissi-Debrah had no choice about the air she breathed, with devastating consequences.” The doctors also told Starmer and Khan they risked losing votes, not gaining them, if they backed away from initiatives to promote better air quality. They wrote: “To kowtow to those who shout loudest is a dangerous precedent, and risks alienating hundreds of thousands of others who may feel that there is no point in voting for Labour if you can’t stick to any of the promises you have made on public health policies.”