If adopted, the move would help passengers make "informed travel choices" when booking, the Civil Aviation Authority (CAA) said, as it launched a consultation on the proposals.

"Providing consumers with accessible, transparent and accurate environmental information is essential to making more informed travel choices," said CAA director of policy Tim Johnson.

"Our new proposals aim to standardise this information across all platforms, enabling passengers to more easily compare the environmental impact of their flights.

"This initiative is a significant step towards greater transparency and improved sustainability in the aviation industry."

The European Union Aviation Safety Agency announced in January that passengers booking flights online will be able to see standardised details on the carbon footprint and efficiency of flights.

Airlines would take part in the "environmental labelling scheme" from next year on a voluntary basis, it added.

The aviation sector is responsible for around three percent of global CO2 emissions but it is one of the most complicated to decarbonise.