ULEZ at Three: Why Sadiq Khan Says His "Hardest Decision" Was Worth It, and What It Means for Drivers Now

Few policies in modern London have divided opinion quite like the Ultra Low Emission Zone. To some, it's a lifeline for children's lungs. To others, it's a stealth tax on ordinary motorists who can't afford to swap their car overnight. This week, Sadiq Khan waded back into that argument, describing the introduction of ULEZ as the toughest call he's made as mayor, while insisting the evidence now proves it was the right one.

Whichever side of the debate you sit on, the ULEZ isn't going away. So it's worth understanding exactly what Khan is claiming, why it matters beyond London, and what it means practically if you drive in or near the capital.

What Khan Actually Said

Writing in the Guardian, Khan revisited the political and personal weight of expanding ULEZ, first to inner London and then, controversially, across all 32 boroughs in 2023. He acknowledges the backlash was fierce: protests, vandalised cameras, a High Court challenge, and sustained pressure from Conservative politicians and some Labour backbenchers who feared it would hit poorer drivers hardest.

His central argument now is that the policy has delivered measurable air quality improvements and reduced pollution exposure for children living and going to school in the zone. He frames this as vindication, not just of the policy itself, but of the principle that unpopular decisions can be the right ones when public health is at stake.

Crucially, Khan is directly answering the criticism that has dogged ULEZ since day one: that it unfairly punishes people who need to drive for work, care duties, or because public transport doesn't serve them well. His response is essentially that the health benefits, particularly for children, outweigh the financial burden on drivers of older, more polluting vehicles.

Why This Argument Still Matters in 2026

It's easy to assume ULEZ is old news. It isn't. Years after the expansion, it remains one of the most contested pieces of transport policy in the country, and the arguments Khan is making now are about more than nostalgia.

First, ULEZ has become the blueprint for clean air zones elsewhere. Bristol, Birmingham, and Manchester have all introduced their own versions with varying rules, charges, and exemptions, and each has faced similar accusations of hitting low-income drivers hardest. Khan's defence of ULEZ is, in effect, a defence of the entire policy model other cities have copied.

Second, the political stakes remain high. ULEZ has been a recurring flashpoint in mayoral elections and a talking point in national politics, with critics arguing it's a symbol of out-of-touch metropolitan policymaking. By publishing this piece now, Khan is clearly trying to shape the narrative ahead of future scrutiny, reminding voters why the scheme exists just as memories of the 2023 backlash start to fade.

Third, and most practically, the zone is still catching drivers out. Enforcement has continued to ramp up, with fines from ULEZ non-compliance running into hundreds of millions of pounds across recent years. For anyone driving an older petrol or diesel vehicle into London, the financial consequences of getting this wrong are real and immediate.

The Legal Framework Behind ULEZ

ULEZ operates under powers granted to Transport for London through the Greater London Authority Act 1999 and subsequent transport legislation, which allow the mayor to introduce road user charging schemes to manage traffic, congestion, and emissions. This is the same legal basis that originally underpinned the congestion charge.

The daily ULEZ charge, currently £12.50, applies to vehicles that don't meet the relevant emissions standards, typically Euro 4 for petrol cars (roughly pre-2006) and Euro 6 for diesel cars (roughly pre-2015). Vans, motorcycles, and heavier vehicles have their own thresholds. If your vehicle doesn't meet the standard and you drive within the zone without paying, TfL can issue a Penalty Charge Notice.

The scheme survived a significant legal test when opponents, including several Conservative-led outer London councils, launched a judicial review challenging the 2023 expansion. The High Court ultimately ruled that Khan had acted lawfully and within his powers, a decision that effectively cleared the way for the scheme to proceed as planned. That case matters because it confirmed the mayor's broad discretion to use these powers for public health and environmental reasons, not just traffic management, setting a precedent that other cities and future mayors can lean on.

It's worth noting that ULEZ enforcement, like the congestion charge, relies heavily on Automatic Number Plate Recognition cameras. Errors do happen. Misread plates, cloned number plates, and vehicles wrongly flagged as non-compliant have all led to PCNs being issued incorrectly, so if a charge doesn't look right, it's always worth checking the details before assuming it's your mistake.

What Drivers Should Know

If you're planning to drive into London, or you live within the zone and drive an older vehicle, there are a few practical things worth keeping in mind.

Check your vehicle's compliance before you travel. TfL provides a free online checker where you enter your registration and get an instant answer on whether your car, van, or motorbike meets the required emissions standard. Don't assume based on the age of your vehicle alone, as some older cars were built to cleaner standards than others of the same era.

Understand the exemptions. Certain vehicles are exempt, including some historic vehicles, and there are grace periods for specific categories such as disabled tax class vehicles and community transport minibuses. These exemptions have changed over time, so it's worth double checking current TfL guidance rather than relying on older information.

Pay on time or set up auto pay. The charge must be paid by midnight on the third day after travelling into the zone. Miss that window and you risk a PCN, which starts considerably higher than the daily charge itself, though it can be reduced if paid promptly. Regular drivers can register for Auto Pay to avoid missing payments altogether.

Don't ignore a PCN if you think it's wrong. If you believe you've been charged in error, perhaps due to a cloned plate, an ANPR misread, or incorrect vehicle details, you have the right to make representations to TfL. This is a formal process with specific evidence requirements, and getting it right the first time matters, since a poorly evidenced challenge can be refused even when you have a genuine case.

Watch for scrappage and support schemes. At various points, TfL has offered scrappage payments and grants to help lower-income drivers and small businesses replace non-compliant vehicles. These schemes come and go depending on funding, so it's worth checking current availability if cost is the main barrier to compliance.

Looking Ahead

Khan's piece is as much about legacy as it is about policy. With ULEZ now embedded in London's transport landscape and other UK cities running their own clean air zones, the debate is shifting from "should this exist" to "how should it be run fairly." Expect continued pressure for clearer exemptions, better support for low-income drivers, and closer scrutiny of enforcement accuracy, particularly around ANPR errors that catch out compliant drivers.

There's also a broader political dimension. Every mayoral term brings fresh questions about whether charges should rise, whether the boundary should expand further, or whether exemptions should be tightened. Given how central ULEZ has become to Khan's public health argument, it's unlikely to be softened any time soon, even as opposition politicians continue to use it as a rallying point against what they characterise as anti-driver policy.

For everyday drivers, the practical reality hasn't changed much: check your vehicle, know the rules, pay on time, and challenge charges you believe are wrong through the proper channels. The political argument over whether ULEZ was worth the pain will run for years yet, but the financial consequences of getting caught out by it are very much in the present.