The topic of the Ultra Low Emissions Zone (Ulez) has been at the forefront of many conversations across London in the last year. 

November 2022 saw London Mayor Sadiq Khan confirm the plans to expand the zone across all of Greater London. 

This will mean anyone who drives a vehicle that does not meet emission standards in the Ulez must pay a daily charge of £12.50. 

It has faced opposition from many in the expansion area, with many refusing and some even councils taking court action against the Ulez expansion. 

Although the topic is currently at the top of many Londoner's conversations, there are questions about what Ulez means and why it's in place. 

News Shopper: The green highlight shows the expansion of the ULEZ.The green highlight shows the expansion of the ULEZ. (Image: TfL)

What does ULEZ mean?

Ulez is short for Ultra Low Emission Zone, which means that the area covered is only reserved for vehicles that emit ultra-low emissions and meet environmental requirements. 

In the UK ultra-low emissions are given to a vehicle that emits below 75g of CO2/km from the exhaust, according to SMMT.

Any type of vehicle can have ultra-low emissions, including cars, vans, lorries, coaches and motorbikes. 

READ MORE: What postcodes are affected by the ULEZ expansion in London?

Why is the ULEZ in place across London?

Plans for the zone were first announced by then-London Mayor Boris Johnson in March 2015 to come into operation in central London in September 2020.

His Labour successer Sadiq Khan introduced the zone early in April 2019, covering the same area as the existing congestion charge. Mr Khan extended it to the North Circular and South Circular roads in October 2021.

From August 29, it is due to be expanded across Greater London. 

As Transport for London (TfL) states: "The aim of the ULEZ is to improve air quality by reducing the number of vehicles in London that don't meet emissions standards.

"94% of vehicles seen driving in the current zone now meet the strict emissions standards on an average day, significantly higher than the 39% in 2017 when the ULEZ was first announced. This has helped to reduce harmful nitrogen dioxide pollution by nearly half in central London."

You can find out more information on the ULEZ at the TfL website.