The European Commission is believed to be ready to force Ryanair to sell its quarter-share in Aer Lingus if the EU turns down its takeover bid.
According to a leaked document, the Commission has laid the legal groundwork which would allow it to make the low-cost airline sell its stake in the national carrier.
It is objecting to the merger of the two - saying that it would lock up the Irish air market if the takeover goes through.
A decision on the proposed merger is expected to be made on June thirteenth.