No new petrol or diesel cars and vans will be sold in the UK after 2040, the Government is to announce on Wednesday in its delayed plan to crackdown on air pollution.
Environment Secretary Michael Gove is expected to announce the move to get motorists to switch to electric or hybrid vehicles as the centre-piece of the Government's Air Quality Plan, which the High Court ordered the Conservatives to publish.
The plan, to tackle rising levels of nitrogen oxide that are posing a major risk to public health, also includes urging councils to clean up air quality along 81 of the most polluted roads in the UK, and insisting they retrofit buses, change road layouts, and improve features such as roundabouts and speed bumps.
But ministers will fight shy of slapping taxes on motorists, and will consider new levies only as a last resort, to scrap their polluting cars earlier.
The Government would allow councils to introduce charges or ban polluting vehicles at certain times of the day if the measures fail to bring down pollution.
A Government spokesman said:
"Poor air quality is the biggest environmental risk to public health in the UK and this government is determined to take strong action in the shortest time possible.
"That is why we are providing councils with new funding to accelerate development of local plans, as part of an ambitious £3 billion programme to clean up dirty air around our roads.
"Our plan to deal with dirty diesels will help councils clean up emissions hotspots - often a single road - through common sense measures which do not unfairly penalise ordinary working people.
"Diesel drivers are not to blame and, to help them switch to cleaner vehicles, the Government will consult on a targeted scrappage scheme, one of a number of measures to support motorists affected by local plans."
The decision on petrol and diesel cars is similar to the ban France made earlier this month and follows car giant Volvo announcing all of its new vehicles will be electric or hybrid post-2019.
The Government was ordered to produce new plans to tackle illegal levels of harmful pollutant nitrogen dioxide after the courts agreed with environmental campaigners that a previous set of plans were insufficient to meet EU pollution limits.
Despite government efforts to delay publication of the plans until after the general election, ministers were forced to set out the draft plans in May, with the final measures due by July 31.
Campaigners have demanded the final plans should include government-funded and mandated clean air zones, with charges for the most polluting vehicles to enter areas with high air pollution, as well as a diesel scrappage scheme.
Their calls for charging zones were backed up by an assessment published alongside the draft plans which suggested they were the most effective measures to tackle nitrogen dioxide, much of which comes from diesel vehicles.
But ministers have been wary of being seen to "punish" drivers of diesel cars, who they claim bought the vehicles in good faith after being encouraged to by the last Labour government on the basis they produced lower carbon emissions.
Air pollution is linked to around 40,000 premature deaths a year in the UK, and transport also makes up a significant share of greenhouse gas emissions.
Environmental law firm ClientEarth took the Government to court over its clean air strategy.
Its chief executive James Thornton said: "The Government has trumpeted some promising measures with its air quality plans, but we need to see the detail.
"A clear policy to move people towards cleaner vehicles by banning the sale of petrol and diesel cars and vans after 2040 is welcome, as is more funding for local authorities.
"However, the law says ministers must bring down illegal levels of air pollution as soon as possible, so any measures announced in this plan must be focused on doing that."
Liberal Democrat Shadow Transport Secretary Jenny Randerson said: "By scrapping the scrappage scheme the government have U-turned on their offer a life line to the millions of owners of diesel cars up and down the country. This is a betrayal to drivers everywhere.
"Air pollution is poisoning our children and leading to causing avoidable deaths across the country. Instead of properly fighting this silent killer the government has flip-flopped, offering tax breaks for cars that they are now banning. The governments feeble attempts to tackle air pollution are too little too late.
"The government needs to take drastic action to end this public health crisis, every moment they sit on their hands more people are breathing in and dying from polluted air.
"The Liberal Democrats have called for all new diesel sales to end by 2025 and a scrappage scheme to help drivers convert to greener vehicles. We are serious about fighting air pollution, this government is not."