Activists gather in August 2015 to demand clean air as Edinburgh Air Pollution Zone to be expanded. Flickr/Friends of the Earth Scotland. Some rights reserved.On 5 May, buried in the noise of the local election results, the government finally published its draft plan for improving air quality and reducing the toxic levels of nitrogen dioxide experienced by people across the UK.

The government had tried to delay the plan's publication until after the general election in a last minute application to the High Court. But they were forced to release it thanks to activist lawyers ClientEarth who have repeatedly held them accountable for breaching pollution regulations.

This latest draft has been described as “weak and incoherent” and nowhere near enough to stop the 40,000 deaths attributed to outdoor air pollution in the UK each year, including asthma, heart disease and lung cancer.

In London, according to research by the Institute for Public Policy Research (IPPR), air pollution has the second biggest impact on public health, after smoking.

The most marginalised people are most vulnerable. In England, the most deprived fifth of neighbourhoods were found to have higher air pollution levels than the least deprived areas. Linked with this, people from ethnic minorities also experience some of the worst air pollution levels. In London, black communities are more likely to be breathing in illegal levels of air pollution than white and Asian ones.

Children are another group at risk. An investigation by Greenpeace and The Guardian earlier this year found that 47,000 babies and children attend nurseries which are close to roads with dangerous nitrogen dioxide levels.

Older people and those with chronic health condition are also at particular risk. A class action is being taken against the government, on behalf of asthma sufferers, for allowing air pollution to exceed legal limits for so long. 

London is cloaked in pollution on an autumnal day in 2012. Flickr/shirokazan. Some rights reserved. As well as being a public health emergency, air pollution is entwined with climate change.

Addressing both things requires burning less fossil fuels, using energy more efficiently, using vehicles with lower emissions and more active travel such as walking and cycling.

Although the UK has cleaned up its act since 12,000 people died in the 1952 Great Smog of London, the government has been resistant to taking the action needed on air pollution, particularly when it comes to cars.

Nitrogen dioxide from diesel vehicles is one of the biggest contributors to modern air pollution, and an area where the UK is falling short. Britain has been sent a final warning by the European Union for its repeated failure to meet nitrogen dioxide limits in 16 areas, including London, Birmingham and Glasgow.

A national network of Clean Air Zones, which charge drivers of the most polluting vehicles for entering the most polluted areas of town, has been identified by ClientEarth – and the government's own documentation – as the most effective way to tackle air pollution from diesel vehicles.

But the government's draft plan – which is open for public consultation until 15 June – although proposing Clean Air Zones as a “focus for action to improve air quality,” does not make charging an essential criteria, leaving it to local authorities to decide.

The plan has been slated for “passing the buck” to local authorities. As ClientEarth lawyer Anna Heslop points out, there are no assurances in the plan that the resources will be made available to local authorities to implement Clean Air Zones adequately enough to curb pollution levels. “Alongside that, the government will have to help drivers of diesel cars to transition to cleaner alternatives whether that's public transport, whether that's buying a new electric vehicle,” she says. A targeted scrappage scheme could be one way of doing this – something else that ClientEarth has been calling for but which was not committed to in the latest plan.

“This a half-baked plan that puts poll ratings before people’s health,” Doug Parr, Greenpeace UK’s chief scientist told The Guardian. “The only real winners are the car makers who, despite misleading customers about their cars’ real emissions and causing this mess in the first place are getting off scot-free.”

Part of the issue is that, while diesel cars might meet standards in testing, in the real world they are exceeding pollution limits; they are designed to perform better in tests than on the road.

In a capitalist system where the car still dominates, reducing diesel air pollution will be hard. Most urban areas remain hostile environments for cyclists, public transport costs have spiralled. In more rural areas it is non-existent.

The cost of motoring has fallen 20% since 1980, while rail fares have gone up 63% and coach fares by 64%. But, according to IPPR, it is likely that diesel cars will have to be completely phased out on London’s roads over the next decade in order to reach compliance with safe and legal levels of air pollution.

The UK, while not the only EU state breaking air pollution limits, has been “at the forefront of resistance to laws aimed at curbing air pollution, reportedly pushing for a weakening of air pollution limits in response to lobbying from the motor industry, calling for car makers to be allowed to far exceed the nitrogen oxides limit.

Keeping up the pressure on the government concerning air pollution becomes even more urgent in the context of Brexit. European Union regulations have been given credit for improvements in UK air quality since the 1970s when the UK was known as the “Dirty Man of Europe”.

The Government has failed to commit to not watering down air pollution standards after we leave the European Union. It is feared that environmental regulation, including those that relate to air pollution, could be quietly removed in the Great Repeal Bill to convert EU law into UK law, expected in June 2017.

Air pollution does not need to be something we just have to live – or die – with in urban areas. We can ask ourselves difficult questions about what we're prepared to do to diminish it but we also need force political action to take down this silent but deadly killer.