Paris and Barcelona are just two of the places urging the European Commission to only allow the sale of zero-emitting buses after a proposed time limit.
A group of European cities and civil society organisations have called on the European Commission to set a deadline of 2027 to end the sale of carbon-emitting buses.
Paris, Barcelona, Rotterdam and Milan are among some of the 11 places that want Brussels to set a sales target, whereby only zero-emission buses will be sold on the continent.
In a letter sent to the European Commission, the signatories say that without action at the EU level, supply will not meet demand if the bloc is to meet its carbon reduction objectives.
"Cities and other civil society stakeholders have written to the Commission asking that 2027 be the day when all new urban buses will be zero emission, and that means they would be either electric or hydrogen," James Nix, freight manager at the European Federation for Transport and Environment told Euronews.
"Cities want more electric bus supply, and this is a very good way to increase the supply of those buses. That will in turn bring down prices. Price is an issue for many cities and greater supply would reduce those price levels."
Nix also said that an EU sales target will give manufacturers the confidence to invest in production.
He added that zero-emissions vehicles in the bloc accounted for 23% of new urban buses in 2021, up from 16% in 2020, demonstrating that a speedy transition can be achieved under the right conditions.
Other cities, including 40 worldwide, have already set their own target of 2025 to only buy zero-emission buses, including every city in the Netherlands.
Speaking to Euronews, the European Commissioner for the Environment, Virginijus Sinkevičius, would not commit to a deadline of 2027 but said the idea of cities doing so themselves is a step in the right direction.
"This is, first of all, [about] the example you show to citizens. So, if cities are not able with their purchasing power to buy and ensure clean mobility to citizens, how can you then demand citizens to buy a clean car when the city is not able to provide clean air buses?" Sinkevičius explained.
"So, I think this is a must. This is a first step which would show a good example to all citizens."
The European Commission will publish its proposal on CO2 emission standards for heavy-duty vehicles, which includes buses and lorries, later this year when any possible deadline could be revealed.