Ryanair says passengers with a boarding pass issued by Kiwi.com will no longer be allowed on its planes.
The airline says the third party website avoids essential aviation regulations by checking passengers in - which should be done directly with Ryanair.
In a statement, it says Kiwi.com does not have authorisation to issue boarding passes to passengers.
Ryanair says it is essential passengers are informed of all safety and regulatory protocols required when travelling.
