The Ultra Low Emissions Zone (ULEZ) will come into force in central London on April 8.

But what exactly is the ULEZ and how could it affect you?

Here’s everything you need to know.

The ULEZ was first proposed by former Mayor of London, Boris Johnson in 2013.

Under the scheme vehicles which do not meet certain emissions standards will be forced to pay a daily charge of £12.50 in a zone which operates 24 hours a day, every day of the year.

Heavier vehicles – lorries weighing more than 3.5 tonnes, and buses and coaches weighing more than five tonnes – will have to pay £100 per day.

All ULEZ charges will be on top of the Congestion Charge which is £11.50 per day.

From October 2021 the ULEZ will be expanded to the North and South Circular roads.

Some discounts apply for residents living in the zone, vehicles registered with a ‘disabled’ or ‘disabled passenger vehicles’ tax class and minibuses not used for business purposes.

Vehicles will need to meet the different emissions standards for the ULEZ based on their vehicles type and the type of particles it emits.

The emissions standards, which cover vehicles sold in the European Union, first appeared in 1992 and are a range of emissions controls that set limits for air polluting nitrogen oxides and particulate matter from engines.

Air quality standards for the ULEZ are:

Euro 3 – which became mandatory for all new motorcycles in 2007

Euro 4 – which became mandatory for all new cars in 2005 and light vans in 2006

Euro 6 - which became mandatory for all new HGVs and buses in 2014, 2015 for cars and light vans and 2016 for larger vans.

You can use the Transport for London (TfL) checker tool to determine your vehicle’s emission standard status.

Drivers who forget to pay the ULEZ will be fined £169, reduced to £80 if paid within 14 days.

So what do London’s different political parties think of the ULEZ?

The Greater London Authority (GLA) Labour group welcomed the introduction.

Leonie Cooper, Labour’s London Assembly environment spokesperson, said: “The ULEZ represents a major change in the way we address polluted air in the capital. We need action now to ensure London achieves zero emissions from road transport by 2050.”

Gareth Bacon, the leader of the GLA Conservatives, criticised Mr Khan for bringing the implementation of the ULEZ into central London 17 months earlier than previously planned – it was originally scheduled for September 2020.

Mr Bacon said: “The Mayor has rushed the introduction of ULEZ in central London, hammering small businesses and the poorest residents who weren’t expecting the charge so early.”

He also said the Conservative group oppose the expansion of the ULEZ to the North and South Circular roads in 2021.

Green party London Assembly Member Caroline Russell said the ULEZ does “not go far enough”.

Ms Russell said: “I’d like to see a London-wide clean air zone that uses smart road pricing, so you pay according to the length of your journey and the level of emissions, rather than a flat fee.”

Caroline Pidgeon the Liberal Democrat London Assembly member said she is a “firm supporter” of the ULEZ.

But she added: “I would like to see far more done to help very small businesses clean up their vans. So far the take up for the ULEZ van scrappage scheme has been pitiful.”

So far only 98 businesses have signed up to a scrappage scheme by Mr Khan to encourage companies to get rid of vans which do not meet ULEZ emissions standards.