Regional Express may struggle to get more landing and take-off slots at Sydney Airport if the airline’s new flights between east coast capital cities are popular with travellers, the airport’s chief executive Geoff Culbert warns.

While Rex has been able to get the slots it needs to launch its first Sydney-Melbourne flights, if there is significant demand for the flights, and for Rex’s planned flights to Brisbane, “they may bump up against capacity limits,” Mr Culbert said.