British Airways gave preference to its “most valuable” customers in allocating seat places on rescue flights after the ash cloud crisis before flight tickets went on sale.

Richard Tams, the airline’s head of UK and Ireland sales and marketing, told delegates that staff worked through the night the morning before flights restarted to ensure key groups had seats before tickets went on general sale.

Vulnerable passengers and groups of school children were prioritised first, followed by “our most valuable corporate customers”.

He said they were not the biggest customers but those who were most supportive. “We did not prioritise our bigger customers, we prioritised our most loyal customers. We worked through the night to make sure our most loyal customers got on an aircraft first before we were giving them [seats] out for sale. We did it in a scientific way.”

Tams added that it was clear the blanket bans were a “massive overreaction” and the cost of the affair was being laid at airlines’ feet because of misapplied legislation. He warned that the cost of claims would be huge and many appeared to be exaggerated, citing one claim for two weeks at the Sandy Lane hotel in Barbados.

He said it would have long-term implications for TMCs because they would have to look at increasing resources to be able to cope with any repetitions and they would also have to consider if corporate clients would be prepared to pay for the extra expense that involved.

Tams praised TMCs for their efforts during the crisis and said they had shown their value to corporates. “If any corporate thinks that they don’t need a TMC or that price is the most important factor, they should think again,” he added.