Aer Lingus is unlikely to be approached by any other potential suitor in the medium to long-term if it rejects IAG's takeover bid, analysts believe.
They also predict that while Aer Lingus has a reasonably strong cash position now, that buffer will come under pressure as it starts a fleet renewal programme in the next few years.
"Aer Lingus has benefited from a capital expenditure holiday," said Davy Stockbrokers analyst Stephen Furlong, who suggested it would be "unwise" for the Aer Lingus board to reject a third approach from IAG.
He believes a bid of around €2.50 a share should be sufficient to give it a decent chance of success.
David Holohan, the head of research at Merrion Capital, said he thinks that a range between €2.60 and €2.70 would focus the minds of the Aer Lingus board, which is headed by chairman Colm Barrington.
Ryanair, meanwhile, is awaiting the outcome - probably this week - of a UK Court of Appeal ruling regarding its Aer Lingus stake. It's already been told by the UK's Competition and Markets Authority that it has to cut its stake to no more than 5pc, but appealed that.