According to The Times, the Mayor is set to introduce an ‘air quality manifesto’ today, principally with aims to disincentivise the use of diesel vehicles and reduce pollution in central London.

The proposals are said to suggest adding £10 to the London Congestion Charge from 2020 onwards for pre-2006 petrol cars and diesels which don’t meet the Euro 6 emissions standards mandated for new cars from next January.Nationally, this proposes a higher vehicle excise duty charge against diesel models, and a fund could also be set up to help cities switch to electromobility.

It follows growing pressure from the European Commission, which launched legal proceedings against the UK in February for illegal levels of harmful air pollution and failing to meet nitrogen dioxide limits set out in the 2008 EU Air Quality Directive.

This showed air pollution limits set for 2010 were still exceeded in 16 zones in the UK, and that even with reduction plans in place it would take 15 of these until 2020 to come in line with the directive. Greater London would take until 2025, it said.

While diesels have been incentivised for carbon reduction, manufacturers have also been criticised for their vehicles not meeting Euro 4 or Euro 5 standards in real-world use. A study of ten cars run by Emissions Analytics and Imperial College London showed all failed to meet Euro 4 and Euro 5, and only one was in line with Euro 3, which came into force in January 2000.

But the proposals have met with criticism for not being strict enough. Simon Birkett, founder and director of Clean Air in London, said these are a ‘backward step’ on air quality issues, and that the proposed ultra-low emission zone is too small, as it only covers around 7% of London.

Instead, Birkett is suggesting measures including tightening up on the removal of particulate filters, banning diesel vehicles from the most polluted areas by 2020 and including cars and light commercial vehicles in the current low-emission zone, adding charges for those which don't meet Euro 4 requirements.

‘Boris is backtracking on his own plan to ban the most-polluting diesel vehicles from Central London from 2020 by allowing these vehicles to drive in for a tenner a day,’ he said. ‘These bold steps are needed to protect public health, reduce inequalities and comply with air pollution laws in legislation since 1999 to be complied with by 2010 (not 2030 as the Government estimates for Boris’s London).’