MPs are calling on the Government and London Mayor Boris Johnson to introduce more stringent measures to dissuade drivers from choosing diesel engined cars – and penalise diesel owners.

In a report released this morning, the London Assembly says Johnson needs to go much further than he has committed to reducing the popularity of ‘deadly diesel’ in the capital.

In its report, ‘Driving away from diesel: reducing air pollution from diesel vehicles’, the group of cross-party MPS says he should introduce the ultra-low emission zone (ULEZ) before the planned 2020 and it should be wider and be covered by more stringent controls.

The report says: “The ULEZ…will rightly penalise diesel vehicles older than the new Euro 6 standard entering central London.

“But even with the newest standard, the testing is inadequate and some certified Euro 6 diesel cars emit several times more pollution than the standard allows in real urban driving.

“The mayor should press for effective new tests to be brought in soon.

“The mayor should also consider further tightening the ULEZ standard as circumstances allow.

“With a government scrappage scheme, the mayor should consider removing all diesel cars from ULEZ exemption – other European cities are considering diesel bans.

“And, supported by effective charging infrastructure, the mayor should bring forward from 2025 the date by which he proposes to restrict the exemption to zero-tailpipe-emission cars.”

And Stephen Knight, chair of the assembly’s environment committee, said: “Where once it was a deadly mixture of soot and smoke from coal-fired power stations and factories that was largely responsible for London’s air pollution, today it is the combustion of diesel that is to blame for much of the problem – with diesel powered vehicles alone responsible for around 40% of London’s nitrogen oxides (NOx) emissions.

“The failure of modern European Union engine standards to deliver the emission reductions expected from diesel vehicles, combined with government policies aimed at encouraging more efficient vehicles, which have indirectly incentivised the uptake of diesel, has left a generation of dirty vehicles on our roads.

“The dieselisation of our fleet shows no obvious signs of stopping either: 50% of all new cars sold in the UK last year were diesel, compared to only around 30% a decade ago.

Yet the drive to diesel cannot be allowed to continue, with the Government having recently been ordered by the Supreme Court to prepare a new air quality strategy that will bring the UK into line with legally binding limits on levels of harmful air pollution as soon as possible.”

The London Assembly’s recommendations:

• The London mayor should introduce the Ultra Low Emission Zone (ULEZ) before 2020 and the zone should be wider and stronger.
• The Government should take forward the mayor’s proposal for a scrappage scheme linked to replacing non-compliant vehicles with low-emission vehicles.
• The mayor should set out - following consultation with the taxi industry - how zero-emission capable taxis will be available from 2018 and how the necessary infrastructure (rapid charging network and/or hydrogen stations) will be delivered.
• The mayor should work closely with the boroughs and national government to show how the whole of London could achieve compliance with European air pollution limits by 2020. 

Knight said further action is needed at a national level and, therefore, the committee’s recommendations are directed towards Johnson and central government.

But the SMMT warned "blanket taxes" were not the answer.

“We are pleased the London Assembly Environment Committee recognises the huge strides made by the automotive industry in reducing vehicle emissions.

"Modern diesels virtually eliminate particulate matter, while the latest Euro 6 vehicles also deliver significant NOx savings. In fact, real world TfL tests using the London 159 bus route show a 95% reduction in NOx from Euro 6 vehicles over their older counterparts. That’s an extraordinary achievement, and industry welcomes new testing for Euro 6 passenger cars in 2017 that better reflects the infinite variations of real world driving conditions.

“The London ULEZ will play a key role in driving the market for these advanced, low emission vehicles, and crucially the 2020 deadline gives consumers and businesses time to adapt. Industry is doing its job by developing the cleanest vehicles in history, and now policy makers must do their bit by encouraging their uptake, and by tackling congestion to keep them moving.

"Air pollution is a local issue and, guided by central government, needs local solutions to encourage uptake and greater efficiency. Blanket taxes or measures that fail to differentiate between new and old technology are not the answer.”

In March a pro-diesel lobby made up of manufacturers and the Society of Motor Manufacturers and Traders launched a campaign to stop what it called the “demonization” of the fuel.

Then, Paul Willis, Volkswagen Group UK managing director, said: "We need to avoid penalising one vehicle technology over another and instead encourage the uptake of the latest low emission vehicles by consumers. The allegations against diesel cars made in recent months threaten to misguide policy making and undermine public confidence in diesel."