Irish Travel Agents Association Chief Executive Pat Dawson has said consumers will be hardest hit by Thomas Cook's decision to close its Irish offices and cancel its summer charter flights from Irish airports.
Speaking on RTÉ's Morning Ireland, Mr Dawson said there will be a basic supply and demand problem.
He said some of the routes where Thomas Cook had ceased to trade will result in more expensive seats in the summer months of July and August.
Yesterday, the country's second largest tour operator announced plans to end its presence in Ireland, with the potential loss of 44 jobs.
Mr Dawson said consumers trying to book last-minute flights will be hardest hit.
"Tour operators, if they undersell capacity, they offer last-minute deals, good prices and so forth," he said.
"The opposite happens to airlines. If you book an airline three or four weeks out it is very expensive."
Mr Dawson said the landscape had changed in the chartered travel business, but people still looked for five-day and ten-day breaks and ITAA members provided these.
He said Thomas Cook would still have an online presence in Ireland, but it would be using airline capacity from scheduled carriers.