Interested in this kind of news? Receive them directly in your inbox. Delivered once a week. Sign Up At present UK airlines are free to operate anywhere within the EU without restrictions on capacity, frequency or pricing. So they can, for example, operate domestic EU routes like Athens to Berlin. Any Brexit deal continuing this freedom must ensure the UK does not quit the aviation ETS so that these airlines’ flights between the UK and Europe (for example, London-Rome) will still be required to purchase allowances. The ETS requires carbon emitters to purchase allowances for around €7 per tonne of CO₂ equivalent, though the price is expected to increase. T&E said excluding UK routes from this purchasing requirement would distort competition and weaken existing European aviation climate measures in a sector responsible for 5% of global warming.  Kristina Wittkopp, legal analyst at T&E, said: “As London works out its future relationship with the EU, it should be able to keep its current level of access to Europe’s aviation market by agreeing to maintain EU rules designed to curb flying’s environmental impact. Undermining action on European aviation’s climate impact would be in no one’s interests and would create an uneven playing field for airlines.” The UK giving unregulated financial aid and subsidies to national airports and airlines would also distort competition and harm the environment by spurring a growth in traffic. To prevent Britain becoming a ‘carbon haven’ for the aviation sector post-Brexit, it is essential that EU state-aid rules continue to apply to the UK, the report finds. Kristina Wittkopp concluded: “The UK's airports and airlines must abide by EU state-aid rules after Brexit if they are to continue their current easy access to one of the world’s largest aviation markets. Anything else would create an unfair advantage and see the UK aviation industry increase traffic and thus emissions through handouts to its domestic aviation industry.” The UK should re-join the European Common Aviation Area (ECAA) as a non-member state after it leaves the EU, the report also found. This would be the UK’s best option, allowing UK registered carriers to continue enjoying all freedoms of the air when flying to Europe. It would, crucially, also mean that all current and future EU environmental legislation would continue to apply to them. Britain should also become a non-voting, fee paying member of the European Aviation Safety Agency (EASA), as this would guarantee adhesion to aviation safety standards and mutual recognition. Note to editors:  Lee, D. et al. Aviation and global climate change in the 21st century (2009). http://elib.dlr.de/59761/1/lee.pdf Read more: Report: Brexit and aviation – what is the best scenario for the environment?