Aer Lingus chairman John Sharman has said he cannot conceive of "any circumstances" in which a Ryanair takeover of Aer Lingus will go ahead. Speaking during a press conference in Dublin, his remarks were echoed by chief executive Dermot Mannion, who said that he could not envisage the Aer Lingus board ever backing a Ryanair bid.

"Let's be unequivocal, I cannot conceive of circumstances in which the Ryanair takeover will be approved by the Aer Lingus board," said Mr Mannion.

This reply was offered after several questioners asked about what would be regarded as an "acceptable offer" from Ryanair.

Mr Mannion said he believed his position was credible in relation to value for shareholders.

"We are very well aware of our fiduciary responsibilities to shareholders. Our value proposition is we can grow shareholder value more as an independent entity than can be the case if Aer Lingus is merged in some way with Ryanair".

When asked what might be the reaction if Ryanair returned with an offer of €4.50, Mr Mannion seemed to suggest that this would not change his view.

"I will repeat what I said. I cannot conceive of circumstances where the Ryanair takeover will be successful".

Mr Sharman said that consumers wanted a choice and they would not be content with the idea that "you can have whatever car you like once it's black".

An Aer Lingus defence document describes Ryanair's €1.4 billion bid as "ill-conceived, contradictory and anti-competitive". It claims that the Ryanair bid significantly undervalues Aer Lingus.

However, Mr Sharman and Mr Mannion endured sustained questioning about how this could be when the company was floated so recently at €2.20 a share and Ryanair was now offering €2.80 a share.

Mr Sharman said the IPO transaction was entirely different from a takeover transaction, as proposed by Ryanair.

"What you got here is an apple and an orange. It's very rare that the apple and the orange are on the table at the same time. The apple, the flotation, was providing capital for this company to invest in new aircraft and to top up the pension scheme. That transaction, or that apple, was of a company coming to market.

"Some guy coming in with a hostile bid for a company that has got €500 million in cash and competes very successfully, that is an orange. It's a different type of company. The guy is trying to take control of his main competitor.

"The two prices, the two transactions are different; there is an apple and an orange and there is no point in trying to equate them.".

Mr Mannion said the company had achieved its objective in the IPO by raising fresh equity for the business and by topping up its pension scheme.

Mr Mannion and Mr Sharman were keen to emphasise that an independent Aer Lingus could offer shareholders greater value than was on offer from Ryanair.

"It's business as usual, but we are accelerating our plans, even in the face of competition on short-haul. We are advancing deliveries, two extra deliveries are coming in 2007. We have also announced 28 per cent growth in long-haul capacity for 2007.

"The message in this document is that Aer Lingus is moving on already, to a time beyond when this bid has expired and has been defeated. We are moving ahead to grow the business and grow shareholder value."

Mr Mannion denied that long-haul routes were suffering, although he conceded that New York was proving challenging at present. "The prognosis though is still very good," he said.

Aer Lingus is flying long-haul to New York, Boston, Chicago, Los Angeles and Dubai. It abandoned Orlando, Florida and Washington DC in recent years.

The Aer Lingus case

• Aer Lingus's performance over the past five years is among the best in the industry.

• Aer Lingus has almost halved its unit costs since 2001 and has a relentless focus on reducing costs.

• Aer Lingus has made a dramatic improvement in its return on capital and is now among the best in the industry.

• Aer Lingus has significant growth prospects on short-haul and on long-haul, where it is in prime position for exceptional long-term growth following the delivery of "open skies".

• Aer Lingus has a target return of 15 per cent per annum on its fleet investment.

• Aer Lingus has a compelling customer proposition and a differentiated strategy.

• Aer Lingus grew its short-haul business out of Dublin airport three times faster than Ryanair in 2005.

• The Ryanair offer prices Aer Lingus at a significant discount to its European peers.