ULEZ expansion given the green light

The Mayor of London’s plans to expand London’s ultra-low emission zone (ULEZ) this August has been a divisive issue across London and the UK, culminating in a judicial review this July that has found it lawful
August 1, 2023

Poor air quality is linked to a variety of respiratory health problems, such as asthma and lung disease, as well as other health issues like cancer, strokes, and a higher risk of dementia[i]. Globally, up to 4.2 million people die prematurely from poor outdoor air quality each year[ii]. London follows similar trends. Around 4,000 Londoners die prematurely each year from air pollution-related conditions[iii]. The highest number of these deaths are occurring in outer London areas[iv]. Vehicle emissions are a significant cause of this air pollution, exacerbated by London’s congestion. Using a calculation of the number of hours lost by drivers to traffic, INRIX claimed that in 2021 London became the world’s most congested city[v]. About half of London’s nitrogen oxide (NOx) emissions come from polluting vehicles[vi]. This pollution is estimated to cost London up to £3.7 billion every year[vii].

Source: PA Media

The public health impacts of air pollution are the basis for plans to expand London’s ultra-low emission zone (ULEZ). ULEZ was drawn up during Boris Johnson’s time as Mayor of London and was then introduced in April 2019 by the current Mayor of London, Sadiq Khan. It aimed to cut pollution in central London by 15%[viii]. The ULEZ boundary was expanded in 2021 to be about 18 times[ix] its original size, encompassing the homes of about 4 million Londoners[x]. The ‘Inner London Ultra Low Emission Zone- One Year Report’ found that harmful pollution emissions within the expanded ULEZ area were reduced by 26% compared with what they would have been without ULEZ[xi]. Sadiq Khan plans to expand ULEZ again to include all London Boroughs, starting from the 29th of August 2023. It is expected that by 2050, ULEZ will have averted over 1 million hospital admissions[xii].


Figure 1: New ULEZ area for 2023

Source: Transport for London

The expansion will mean that entering the Greater London Authority Boundary in a light vehicle, such as a car, small van, or motorbike, that does not meet minimum emissions standards will cost the driver a charge of £12.50 a day[xiii]. If this charge is not paid within three days, the driver will be issued a penalty charge notice of £180 or £90 if paid within 14 days[xiv]. According to the Mayor of London, over 4/5 of drivers in outer London won’t be affected by the change[xv]. A £110 million scrappage scheme, and exemptions until 2025 for community transport vehicles and until 2027 for people with disabilities, are intended to help those affected[xvi].

Although public health is seen as the reason for ULEZ expansion in the discourse, there are environmental benefits of the plan too

The Mayor of London has also highlighted the carbon dioxide reductions of the ULEZ scheme, stating that “ULEZ is also tackling the climate emergency”[xvii]. After six months of the ULEZ scheme being in place, CO2 emissions from central London were 4% lower than they would have been without the scheme. If ULEZ expands, there is greater potential for carbon dioxide reductions. ULEZ also contributes to the use of more sustainable travel modes like walking, cycling, and public transport. There was a 3-9% reduction in central London traffic flows in May and September 2019 compared to 2018[xviii]. However, these traffic flow reductions may have also been influenced by other factors, such as private hire vehicles no longer being exempt from the congestion charge. Sustainable transport is also aided by ULEZ because money from the scheme is reinvested into London’s transport network, including the expansion of bus routes in outer London[xix].

There is a strong support base for the new scheme

51% of Londoners believe the ULEZ expansion should be implemented, whilst 27% believe that it should not[xx]. Demographics play a key factor in support, with the expansion being more popular amongst people under 50 at a 56% support rate. Additionally, 62% of Londoners without access to a garden or private outdoor space are in favour of the expansion[xxi]. Several organisations have expressed their support of the expansion, such as the grassroots organisations Mum’s for Lungs and Islington Clean Air Parents.

Source: Islington Clean Air Parents


Not everyone is happy with the expansion, however

Source: PA


The plan to expand ULEZ has faced fierce criticism, particularly from people living on the outskirts of London, where there are fewer transport connections. It has been described by Teresa O’Neill, the leader of Bexley Council, as “the mayor’s money-making scheme”. Some have said that it will unfairly impact people living in outer London who have mobility issues, lower incomes and cannot afford a new car, or who work at night and have no option but to drive or feel safer doing so. Others argue that now is not the time for increasing costs when bills and prices have been soaring. However, according to the Mayor of London, 54% of Londoners saw the ULEZ as positive in 2022, the same as the previous year[xxii]. Accordingly, this has been argued to suggest that the cost-of-living crisis has not impacted support. Many in opposition to the expansion feel their voices have not been heard.

On the 12th of January, the Conservative-led councils of Bexley, Bromley, Harrow, Hillingdon, and Surrey served the Mayor of London with a pre-action protocol letter stating five grounds for judicial review[xxiii]. However, the High Court only granted three grounds of the appeal. The first ground for appeal relates to the legal basis for the scheme and claims that there was a failure to follow statutory procedures. The second, is that people did not have a chance to make an informed response to the consultation process. The third concerns the £110 million scrappage scheme, and the potential to include non-Londoners in this scheme. The judicial review commenced between the 4-5th of July.

Between the judicial review starting and the judgement, ULEZ gained significant media attention when it was blamed for Labour’s defeat in the Uxbridge by-election. On the 28th of July, the ULEZ expansion was found to be lawful by High Court judge, Mr Justice Swift. Sadiq Khan has praised the result but has said that he will “do everything possible to address any concerns Londoners may have”[xxiv].



[i] Transport for London- ULEZ Expansion 2023 & Green Alliance- The Case for Clean Air Zones

[ii] Green Alliance- The Case for Clean Air Zones

[iii] BBC- ULEZ Expansion: How will it Affect You?

[iv] Transport for London- ULEZ Expansion 2023

[v] INRIX- INRIX 2021 Global Traffic Scorecard: As Lockdowns Ease UK City Centres Show Signs of Return to 2019 Levels of Congestion

[vi] Mayor of London- ULEZ Reduces 13,500 Cars Daily & Cuts Toxic Air Pollution by a Third

[vii] Ibid

[viii] BBC- ULEZ Expansion: How will it Affect You?

[ix] Mayor of London- Mayor: Ultra-Low Emission Zone to expand up to North & South Circular

[x] The Guardian- London Mayor has no Legal Power to Expand ULEZ Zone, High Court Told

[xi] Mayor of London- Inner London Ultra Low Emission Zone- One Year Report

[xii] Ibid

[xiii] Transport for London- ULEZ Expansion 2023 

[xiv] Ibid

[xv] Mayor of London- The Ultra Low Emission Zone (ULEZ) for London

[xvi] Ibid

[xvii] Mayor of London- ULEZ Reduces 13,500 Cars Daily & Cuts Toxic Air Pollution by a Third

[xviii] Ibid

[xix] Transport for London- ULEZ Expansion 2023

[xx] Mayor of London- Nearly twice as many Londoners support expansion of the ULEZ

[xxi] Ibid

[xxii] Mayor of London- Nearly twice as many Londoners support expansion of the ULEZ

[xxiii] BBC- ULEZ Expansion: Judicial Review to be Held over Plans 

[xxiv] Sky News- ULEZ Expansion Legal, High Court Rules

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Gemma Drake
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Gemma recently graduated with a degree in International Development. She is currently studying for an MSc in Sustainable Urbanism, which examines urban planning and urban design through a sustainability lens. “I’m passionate about addressing sustainability challenges in a holistic and pragmatic way. Zero Carbon Academy's diverse range of services targets many of the areas that need support if we are to transition to a liveable future. I’m excited to see the impact that the Academy makes.”

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