As the Unmanned Aircraft Bill goes before parliament for a second reading, the British Airline Pilots Association (BALPA) says new European research backs its concerns that the number of drone flights in controlled airspace is being underestimated.
The research by Eurocontrol involved comprehensive monitoring of airspace around the Latvian airport of Riga.
Latvian airspace has similar restrictions on drone operations to the UK and Riga has a similar number of movements to London Luton Airport with the same single-runway configuration.