The former chief scientific adviser has admitted it was wrong to cut fuel duty on diesel vehicles after being hoodwinked by the car industry, as the mayor of London launched a crackdown on vehicle pollution.

David King, who until last week served Labour and Tory governments as special representative for climate change, said he was misled by carmakers over the amount of poisonous nitrogen oxides (NOx) diesel cars would emit on the road.

The number of diesel cars sharply increased after the Labour government cut fuel duty on diesel vehicles in 2001.

Challenged about the move on BBC Radio 4’s Today programme, King said on Tuesday: “It turns out we were wrong.”

David King. Photograph: Alfred Cheng Jin/Reuters

He said the government at the time wanted to encourage more people to drive diesel cars because they were said to emit less carbon dioxide than petrol vehicles. He said he was aware of warnings that diesel vehicles produced more toxic nitrogen dioxide, but he and the government had wrongly assumed this could be controlled by new technology and European regulations.

“I was in very close contact with the industry that was producing these catalyst trap systems and I was convinced that they could manage the problem,” he said. “What we know now, from the Department for Transport emission results from very extensive tests of vehicles, is that a large number of diesel-driven vehicles on the road in London are emitting more than 12 times the Euro 6 limit.”

Asked whether he was misled by the car industry, King cited the Volkswagen emissions scandal. “They [VW] were designing into the engine of vehicles a system that would in effect produce a very good result on the test bed and then deteriorate when it was on the road,” he said.

But King said all diesel car manufacturers “are managing a system whereby the test bed produces the results they want”.



Launching plans to speed up the expansion of tougher rules on vehicle pollution, the mayor of London said car industry claims about vehicle emissions were unreliable. “Frankly, we don’t trust the manufacturers,” Sadiq Khan said. He has set up what he calls the world’s first independent monitoring of vehicle emissions in a joint initiative with his counterpart in Paris.

Sadiq Khan and Paris mayor Anne Hidalgo lead joint air pollution initiative. Photograph: Gonzalo Fuentes/Reuters

The initiative, which will be launched in October, will rely on road rather than laboratory test figures.

Under this and other proposals, drivers of the most polluting vehicles will have to pay £12.50 to enter an ultra-low emission zone [ULEZ] in central London from April 2019, a year earlier than scheduled. The charge would apply to all vehicles, including diesel cars, by 2021, Khan said.

Khan also confirmed that by 2020 he could extend the zone London-wide for heavy goods vehicles, including buses and coaches. From October, a £10 toxicity fee inside the congestion charge zone will be introduced for petrol and diesel cars registered before 2006.

Up to 10,000 vehicles each day are expected to face the T-charge, which comes on top of the congestion charge, meaning it will cost £21.50 to drive an affected vehicle in central London from 7am to 6pm on weekdays.

Air pollution is linked to 9,000 early deaths a year in London, one of many places hit by the UK’s air quality crisis, which has prompted the European commission to issue a “final warning” to the government for repeated breaches of legal limits.

Khan said: “The air in London is lethal. We think that half of air pollution comes from vehicles. My plans will lead to a 50% reduction in NOx in 2020.”

But he urged central government to do more to tackle other forms of pollution. “I’m doing all that I can. What I’m saying to the government is that if you are going to help us fix the air in London and across the country we need a package of measures from you: a national diesel scrappage fund, a new clean air act … but also reforming vehicle excise duty.



“The science now tells us that diesel vehicles cause more than four times the pollution than petrol cars. A national diesel scrappage fund would mean low income families, charities, businesses would get help to move away from diesel.”

Khan was asked why he could not ban diesel vehicles. “The newest diesels are less polluting than the old petrols,” he said. “All the evidence we have is that people will change their behaviour as a consequence of the toxicity charge.”

The government is expected to launch a national air pollution plan in the coming weeks after being ordered to reduce the illegal level of nitrogen dioxide in most air-quality zones. The plan could lead to polluting vehicles being charged for entering dozens of city and town centres.

Anna Heslop, a lawyer at ClientEarth, which successfully sued the government over air pollution, said Khan’s measures were a significant move.

But she added: “All options need to be on the table, including a London-wide ULEZ for all vehicles to protect the health of all Londoners. The high court made it crystal clear that the government and therefore the mayor must do everything in their power to clean up London’s air as soon as possible.”

