Aer Lingus have released a strong statement which says Ryanair should never have launched a takeover bid for the airline.
The carrier was commenting after the EU blocked Ryanair's bid earlier.
The budget airline has described the decision as a "political one", which isn't based on competition law.
Ryanair bosses have now instructed company lawyers to appeal the block.
Aer Lingus meanwhile says it is looking forward to continuing to assist the UK Competition Commission in its ongoing investigation into the anti-competitive effects of Ryanair’s minority shareholding.