Aer Lingus customers who booked flights to the US for just €5 have been told by the airline that their bookings have been cancelled.

Aer Lingus commercial director Enda Corneille has told RTÉ News that the number of bookings which it has cancelled as a result of a pricing error on its website is closer to 300, significantly more than the airline previously estimated.

The airline also points out that a booking may involve more than one person travelling, leaving Aer Lingus exposed to a far greater potential financial loss on the affected flights than might generally be perceived.

However Chief Executive of the National Consumer Agency, Ann Fitzgerald, says she has been in contact with Aer Lingus and is seeking a meeting with senior management at the airline to discuss the controversy over cancelled bookings.

The airline said the business class flights, which were advertised on the Aer Lingus website yesterday, were priced incorrectly due to a technical error.

Aer Lingus has apologised for the error.

It says the glitch affected customers between 7.30am and 9am yesterday, when promotional fares on its transatlantic route were loaded onto the website accidentally.

The airline says that on legal advice it decided not to compensate the customers.

In emails and text messages to the customers, Aer Lingus said: 'Due to a technical error in our reservation system for a brief period a small number of bookings were priced incorrectly. This email is to notify you of cancellation of your booking and to advise no funds will be deducted from your account.'

Speaking on RTÉ Radio's Morning Ireland, Dermott Jewell of the Consumers' Association said: 'Customers had a binding contract with Aer Lingus. They booked and paid to bind the contract. Realistically Aer Lingus is going to have to do something to abide by the bookings and to help the customers.'

Enda Corneille, Director of Corporate Affairs at Aer Lingus, said anyone who booked a business class ticket, which usually retails at about €1,775, and got it so cheaply should know there was a mistake.

He said: 'When you are selling seats on the front of the site quite openly for €249, to sell a business class seat for a fiver is a genuine mistake. People are going to know there's something up.'