Mr Fankhauser said British travellers should expect a travel cost increase of at least five percent when looking for their 2018 holidays abroad.
The Thomas Cook boss told BBC Radio 4 Today: "In destinations like Spain where we pay our hoteliers in euros, we see out of the weaker pound, we see a certain price increase as well from the currency.
"We will have about five to ten percent price increase in Spain for sure."
SKY NEWS/GETTYMr Fankhauser said British holidaymakers will see a five to ten percent travel price hike
Mr Frankenhauser' warning follow a dip in the pound following Prime Minister Theresa May's recent Brexit update speech in Florence.
Data from Hotels.com showed that Britons are already paying 35 percent more for their holidays in Europe since Brexit
According to the travel booking