The controversial expansion of London's ultra-low emission zone (Ulez) has come into effect.
The move has made the capital the world's largest pollution-charging area.
Motorists who drive in Greater London in a vehicle that does not meet minimum emission standards must now pay a £12.50 daily fee or risk a fine.
London mayor Sadiq Khan, who has faced strong opposition to the expansion, insisted on Tuesday that the scheme was not "anti-car", claiming that nine out of 10 cars in outer London are already compliant.
Watch: What is London's Ulez and how will it affect drivers?
The new rules have been dogged by controversy. Five councils in outer London tried to prevent the expansion before losing a High Court battle - and another six councils just outside the zone have refused to sign an agreement with TfL to install warning signs, leaving motorists without notice and facing fines.
On the eve of the expansion, a tribunal also found that Ulez signs "could be unlawful" after it ruled in favour of a scaffolder who refused to pay a fine saying the signs did not provide enough detail about the penalties.
There have also been regular protests against the plan and anti-Ulez vigilantes have targeted enforcement cameras installed in the new areas.
To mitigate the impact on people, a £160m scrappage scheme run by Transport for London (TfL) enables residents, small businesses, sole traders and charities scrapping non-compliant cars to claim grants.
Yahoo News runs through all the key information you need to know:
What is Ulez? The ultra-low emissions zone was introduced in April 2019 to tackle poor air quality in London. It operates 24 hours a day, seven days a week (except Christmas Day) and requires drivers of vehicles that do not meet emissions standards to pay a daily charge.
The scheme is administered by Transport for London (TfL) and following its expansion on Tuesday, now covers all of the boroughs inside Greater London.
Read more: This is what happens if you refuse to pay the ULEZ charge (News Shopper)
How much does Ulez charge? Vehicles that don't meet the emissions standards required by the Ulez zone must pay a £12.50-per-day charge to drive in or through the zone. The charge covers a period from midnight to midnight. Vehicle owners who fail to pay the charge by midnight on the third day following the journey into or through the Ulez zone can be fined £180.
Read more: Find out more about TFL's ULEZ rules (TfL)
What is the scrappage scheme and who can apply?
The scrappage scheme allows those whose vehicles do not comply with Ulez to access grants if they scrap their vehicles.
When the change to boundaries was announced for the zone, the scrappage scheme was also expanded to cover Greater London.
The scheme previously included child benefit recipients, low-income and disabled people but now all Londoners with non-Ulez compliant cars or motorcycles can apply.
All London residents can apply for up to £2,000 for scrapping a car or up to £1,000 for scrapping a motorcycle.
Small businesses and sole traders will also get £21,000 to scrap up to three vans, with £27,000 available for charities to replace three minibuses.
Other extra support includes higher payments for switching to an electric vehicle, for charities with old vans, and for retrofitting an existing vehicle. Grants for replacing wheelchair-accessible vehicles will double to £10,000.
To find out if you are eligible for the scrappage scheme, you have to check via the TFL website.
First it will ask for your postcode then will tell you if you're eligible and how much help you can get.
Which cars are exempt from Ulez?
Cars that do not have to pay Ulez include those that meet Euro emissions standards for their particular vehicle class. According to TfL, these are:
Euro 3 for motorcycles, mopeds, motorised tricycles and quadricycles (L category)
Euro 4 (NOx) for petrol cars, vans, minibuses and other specialist vehicles
Euro 6 (NOx and PM) for diesel cars, vans and minibuses and other specialist vehicles
In total, the Greater London Authority believes more than 90% of vehicles in the capital will not have to pay the charge.
Read more: What is the best used car that’s exempt from Ulez charges? (Telegraph)
What is the Ulez NOx limit?
To comply with London's Ulez regulations, a vehicle must meet the Euro 6 emission standards for Nitrogen Oxides (NOx) and particulate matter (PM). This requires the vehicle to not emit more than 80mg/km of NOx and 4.5mg/km of PM.
Read more: What is the ultra-low emission zone? (PA)
Why are people against it?
Those who do not back the expansion, or indeed the existence, of Ulez, argue the system unfairly penalises those who are unable to afford newer cars that meet the emissions targets laid out by the scheme.
A petition on Change.org protesting against the expansion of Ulez described it as a "stealth tax" that should not be expanded to residential areas where the transport links are poor.
“Our residents are telling us that low-income and elderly households are going to be most keenly impacted by this tax, as will local businesses,” Ian Edwards, leader of Hillingdon Council, told the Evening Standard.
Read more: Ulez risks driving up pollution outside London, experts warn (The Telegraph)
Why do people support it?
Those in favour of the scheme say it is necessary to reduce harmful vehicle emissions and make the capital's air cleaner and safer for those who live and work there.
Indeed, there are concerns that some of London's outer boroughs are seeing harmful levels of pollution – and Khan has argued clean air is a right that should not be reserved for those living in the centre of the city.
Oliver Lord, head of strategy for the Clean Cities campaign, pointed to Cromwell Road in Kingston, south-west London, as an example of an area where pollution was out of control.
“This has been showing illegal levels of nitrogen dioxide for 12 years, even though they were meant to end in 2010,” he told The Guardian. “A whole generation of kids has grown up in Kingston with harmful levels of air pollution.”
“We shouldn’t be setting a carer with a car against a mum looking after her son with asthma in hospital.”
Read more: 'Expanding the ULEZ is good but it won’t work by itself' (The Conversation)
How did Rishi Sunak try to block it?
In mid-August, the prime minister and his government decided against overruling the expansion of Ulez after receiving advice from lawyers, according to The Telegraph.
The ministers were contemplating the use of a legal power to oppose the mayor's move to extend the zone to cover all of Greater London.
The reason cited was that it was "inconsistent with national policies." This bid would be rejected if challenged by City Hall in court, according to legal advice.
Rishi Sunak ‘overruled from blocking Sadiq Khan’s Ulez expansion’ (Evening Standard)
Ulez cameras vandalised
The resentment in some areas towards Ulez has led to vandalism of Ulez cameras.
The Metropolitan Police said it had recorded 288 crimes relating to the cameras as of 1 August and released an image of a suspect.
Anti-Ulez vigilantes have repeatedly targeted the cameras in recent months.
Read more: More than half of London’s Conservative voters back damage to cameras, YouGov poll suggests (LondonWorld)
Unusual ways to avoid Ulez payments
Despite anger over the new charge from motorists, some have taken advantage of the new rules to explore alternative options.
Certain vehicles, such as military vehicles, specialist agricultural vehicles, and excavators, can be utilised to bypass the charge.
But be careful to check the exact rules from TfL.
Weird ways to beat the Ulez charge as tank dodges rules with loophole (Evening Standard)
Scaffolder wins legal battle against Ulez
Noel Wilcox, 48, who runs a scaffolding company in Hertfordshire, won a legal battle against Ulez after refusing to pay £11,500 in fines for driving a company lorry to and from a depot in north west London.
A tribunal found in his favour that Ulez signs "could be unlawful", saying he had argued correctly that signage did not provide enough detail about the penalties.