In the dispute over the stricter EU climate protection requirements for air traffic, the low-cost airline camp around Ryanair has opposed the alliance between Lufthansa and Air France KLM.
Ryanair, Easyjet, Wizz and Jet2 demanded on Friday that airlines should also have to buy pollution rights in the European emissions trading system (ETS) for long-haul flights in future, contrary to what was planned.
According to data from the EU aviation authority Eurocontrol, long-haul flights cause a good half of all carbon dioxide emissions in European aviation.
The network airlines only paid for 19 percent of their CO2 emissions in the ETS, as this is limited to intra-European air traffic.
The companies that only fly in Europe, such as the four low-cost airlines, would have to pay for 80 to 90 percent of their CO2 emissions in the ETS.
As part of its "Fit for 55" climate protection package, the EU Commission has proposed that the industry be gradually asked to pay more in the ETS. However, the system should remain limited to Europe. Long-haul flights were left out from the start because the non- EU airlines and their home countries was not enforceable At a global level, climate protection in air traffic is to be regulated via the Corsia system, the effectiveness of which is disputed.
The alliance of Lufthansa and almost 20 other companies called for equal treatment with the competition outside the EU for the long-haul business of the network airlines.
One option is to exempt feeder flights to long-distance routes within Europe from the ETS.
These demands would be "unreasonable and unjustified", criticized the low-cost airlines, which do not offer long-haul flights.
"There is no reason to exclude flights, especially the most polluting indirect ones that require at least two flights to reach their destination," said Ryanair CEO Michael O'Leary.
The climate protection requirements should apply to all outgoing flights, regardless of destination, demanded Wizz Air boss Jozsef Varadi.
The low-cost airlines are supported by the environmental organization Transport & Environment.