The Thomas Cook logo is seen in this illustration photo January 22, 2018. REUTERS/Thomas White/Illustration

ISTANBUL (Reuters) - Turkey could miss out on 600,000-700,000 tourists a year following the collapse of British tourism agency Thomas Cook TCG.L on Monday, the head of Turkey's Hoteliers Federation (TUROFED) said.

TUROFED chairman Osman Ayik said the estimate was based on the number of tourists that had come to Turkey with Thomas Cook in recent years. He said those tourists may now decide against returning with other travel agencies.

The world’s oldest travel firm collapsed on Monday, stranding more than half a million holidaymakers around the globe and sparking the largest peacetime repatriation effort in British history.

Ayik said there were currently 45,000 tourists in Turkey from the United Kingdom and other European countries who had traveled with Thomas Cook.

Dalaman Airport’s website showed at least seven flights to several UK destinations scheduled to depart on Monday had been canceled.

Tourism is a major source of income for Turkey, helping to shore up its current account deficit, especially in the summer months. About 40 million tourists visited in 2018, bringing in a revenue of $29.5 billion, according to official data.

“There are a large number of small businesses whose fates depend on Thomas Cook, especially in Mugla, Dalaman and Fethiye,” Ayik told Reuters, referring to popular destinations on Turkey’s western coast.

He said Thomas Cook owed 100,000-200,000 pounds each to some small hotels, which could suffer as a result of the travel agency’s collapse.

Turkey’s Tourism Ministry said earlier that it was working with the Finance Ministry to extend a loan support package to businesses that were affected.