The European Commission is expected to reject Ryanair's proposed purchase of Aer Lingus.
If the €1.48bn bid were stopped by the commission, it would be only the 20th among the more than 3,000 cases considered by the European Union's executive arm since 1990.
The report from a source quoted by Reuters comes after a market test found Ryanair's latest proposed remedies for competition problems were insufficient.
