Ryanair could cut jobs in countries where the budget carrier is facing strikes.
Europe’s largest airline issued the warning after it blamed rising employment costs in part for a 20% slump in quarterly profits.
Having been forced to recognise trade unions from last December, Ryanair is facing strikes for the first time as staff protest over pay and conditions.
The latest disruption will focus on Ireland today where pilots are due to walk out after 25% voted to strike, Belgian and Spanish cabin crews will strike on Wednesday and Thursday.
Ryanair said in a statement: “While we continue to actively engage with pilot and cabin crew unions across Europe, we expect further strikes over the peak summer period as we are not prepared to concede to unreasonable demands that will compromise either our low fares or our highly efficient model.
“If these unnecessary strikes continue to damage customer confidence and forward prices/yields in certain country markets then we will have to review our winter schedule, which may lead to fleet reductions at disrupted bases and job losses in markets where competitor employees are interfering in our negotiations with our people and their unions.
“We cannot allow our customers flights to be unnecessarily disrupted by a tiny minority of pilots.”