LOT Polish Airlines is ramping up services from London City airport with the introduction flights to Budapest.
The twice-daily service to the Hungarian capital joins a connection to Warsaw which started in January.
Flights to Vilnius in Lithuania are due to be added on May 1 from the Docklands airport.
The new services have been made possible by the Polish flag carrier acquiring four 106-seat Embraer 190 regional jets which are capable of flying from London City.
The airport’s aviation director Peter Downes said: “It means that, for the first time, the Hungarian capital joins our route map, adding another major European city that leisure passengers will love and a convenient service for business trips.”