The United Kingdom has already announced plans to ban sales of vehicles powered by internal combustion engines but some people are pushing for the ban to go into effect sooner than originally planned.

According to Reuters, London Mayor Sadiq Khan has teamed up with leaders of other cities to push the government to ban sales of new petrol and diesel vehicles by 2030. This is ten years ahead of the government’s plan which still hasn’t been fully detailed.

In a statement, Kahn said “Banning the sale of new petrol and diesel vehicles by 2030, providing support to deliver Clean Air Zones in cities and introducing a national vehicle renewal scheme will dramatically improve our air quality and our health.”

City AM reports Khan – along with the leaders of Bradford, Bristol, Cardiff and Oxford – will meet with the Secretary of State for the Environment on Wednesday during a national air quality summit in London. The group will try to convince secretary Michael Gove that faster action is need to ensure the health of British citizens. They also want the government to launch a so-called “renewal scheme” which will attempt to get owners of older vehicles to exchange them for something more eco-friendly.

It remains unclear if the group will be able to sway the government but the leaders represent cities which have a combined population in excess of 20 million people. This is slightly less than a third of the UK’s population and it will undoubtedly put pressure on the government to act.

Speaking of the latter, the government is expected to announce details about its “Road to Zero” plan in the near future. A lot of questions remain about the plan and one of the biggest is whether or not hybrid vehicles will be subject to the ban.