Holidaymakers are being warned not to buy their foreign currency at the airport - as many are offering less than one euro to the pound.
A recent survey of airport bureaux de change was carried out by travel money firm FairFX on Monday morning.
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It found that the continuing fall in sterling's value means that the average rate available at 17 airport bureaux de change is now 99 euro cents to the pound, reports the BBC.
The site says that the worst rate is 88 euro cents at Moneycorp at Southampton airport and the best is €1.06 from the Change Group at Glasgow Preswick airport.
The value of the pound has fallen sharply since the Brexit vote in June.
Financial expert Martin Lewis, of MoneySavingExpert.com, blasted companies for taking advantage of consumers.
He tweeted a picture of a Moneycorp exchange rate board at Gatwick and wrote: "No wonder they shouted at me 'you're not allowed to photograph that'. Disgraceful exchange rate profiteering."
No wonder they shouted at me "you're not allowed to photograph that". DIsgraceful exchange rate profiteering at Moneycorp Gatwick. pic.twitter.com/jdz0Nnzzck
— Martin Lewis (@MartinSLewis) October 9, 2016
According to the Telegraph, a spokeswoman for the firm said they had to offset "significant cost... from ground rent and additional security, to the cost of staffing the bureau for customers on early and late flights."
She added that it is better for customers to pre-order their travel money online and collect it at the airport.
The current wholesale rate is €1.11 to the pound.
Speaking to the BBC, the FairFX chief executive, Ian Strafford-Taylor, said: "Currency firms operating in airports are known to offer the worst exchange rates down to taking big profit margins and today are shockingly offering holidaymakers below one euro to the pound."
He added that if the pound falls even further, "rates as poor as this could be seen at airport providers up and down the country".
For information on the best and cheapest ways to get travel money, visit MoneySavingExpert.com.