Ryanair Chief Executive Michael O'Leary said the concerns of its fellow Aer Lingus shareholder, the Irish government, on the potential sale of the airline to the owner of British Airways are misplaced.

Prime Minister Enda Kenny said on Sunday that International Consolidated Airlines Group (IAG) must provide a "cast iron permanent guarantee" regarding flights serving Ireland if the government is to even consider a bid for Aer Lingus.

"More people fly to other London airports than fly to Heathrow on a daily basis from Ireland so much of the noise about Aer Lingus or connectivity or Heathrow slots is entirely misplaced in what is a rapidly changing modern aviation world," O'Leary told Ireland's national broadcaster RTE.