Motorway speed limits could be lowered and clean air zones expanded across the UK under a draft plan that ministers published on Friday aimed at tackling the country’s illegal air pollution levels.
An option to cut average speeds on polluted motorways from 70 to 60 miles per hour is among the main proposals in a strategy the government was forced to release after losing a court battle to keep its air quality plans under wraps until after the June 8 general election.
A “targeted” national scrappage scheme is also included in the proposals, along with a scheme to retrofit buses, black cabs and heavy goods vehicles between now and 2020.
The consultation document is the second that environmental lawyers have prodded ministers to produce in the last two years to deal with dirty air that researchers say is linked to 40,000 premature deaths in the UK each year.
About 23,500 early deaths have been blamed on high levels of nitrogen dioxide, a gas produced by the diesel vehicles that make up nearly half the cars sold in the UK each year.
The UK has been struggling to comply with EU air pollution standards that were originally due to have been met in 2010.
It was one of five countries that received a final warning from Brussels in February for repeatedly failing to address breaches of air pollution limits in London and 15 other areas including Birmingham, Leeds and Glasgow.
The problem has posed political difficulties for ministers trying to address a rising public outcry over unsafe city air without angering drivers initially encouraged to buy diesel cars because they produced fewer carbon emissions than petrol vehicles.
The UK’s last plan to tackle air pollution was released in December 2015 and proposed local authorities crack down on older diesel buses, lorries and cabs but not passenger cars.
That document showed EU limits were being exceeded in 38 out of 43 UK air quality zones but even with the proposals it outlined, most of these areas would not be compliant until 2020 – or 2025 in the case of London.
The ClientEarth environmental law firm accused the government of foot-dragging and took it to court to force it to take speedier action.
In November last year, a High Court judge agreed the government’s earlier efforts were “flawed” and ordered ministers to go back to the drawing board and come up with a better plan no later than April 24 this year.
After the prime minister, Theresa May, unexpectedly called a snap election for June 8 last month, the Environment Secretary, Andrea Leadsom, asked the court to extend the deadline, claiming “purdah” pre-election rules made it necessary.
However, the court dismissed the government’s application and ordered the draft plan be published by May 9, just after this week’s local elections.
While diesel engines are usually more fuel efficient than petrol alternatives, they emit more nitrogen dioxide and particulate matter but authorities say they believed these pollutants could be dealt with by progressively tougher emissions standards.
The flaws in this strategy became apparent in 2015 when Volkswagen admitted it had installed illegal software in diesel cars that allowed the vehicles to understate emissions in laboratory tests while polluting on the open road.