As the UK government began the Brexit process Wednesday with a letter formally informing the European Commission of its intention to leave the European Union (EU), Ireland’s Ryanair called on Britain’s legislators to “put aviation at the forefront” of negotiations with the EU to formulate a coherent plan to ensure flights to and from Europe after March 2019. As the UK leaves the EU and its Open Skies system at that time, the UK government will have needed to negotiate a bilateral agreement with Brussels to allow flights to and from Europe to continue. Ryanair warned that the failure of UK and EU to reach an agreement will trigger a reversion to World Trade Organization rules, which do not cover aviation, and raise the possibility of no flights between Europe and the UK starting in March 2019. The airline stressed that it could start cutting schedules within 12 months because it must release its summer 2019 timetables next March.

“Some nine months on from the Brexit referendum, we are no closer to knowing what effect it will have on aviation,” Ryanair chief marketing officer Kenny Jacobs said in a written statement. “It [has] become worrying that the UK government seems to have no plan B to maintain Britain’s liberalized air links with Europe, in the absence of remaining in the 'Open Skies' regime.

“The best we can hope for is a new bilateral agreement between the UK and EU; however, we worry that Britain may not be able to negotiate such a bilateral in time for the release by airlines of summer 2019 schedules in mid-2018.”

Ryanair said it has already “pivoted” growth away from the UK and other EU airports in anticipation of Brexit, basing no additional aircraft at its 19 UK airports this year and cutting its planned growth rate from 15 percent to 6 percent.