Nearly 17 per cent admitted to deceiving airline or hotel staff to bag a better room or seat in a poll of over 8,000 Britons carried out by the website TripAdvisor.

Their dishonest tendencies do not stop at travel upgrades, either. A separate survey of over 12,000 holidaymakers showed that one in eight had also pretended to be sick so they could extend a holiday.

“Treats and upgrades can be a real perk of travel but there’s a danger that we’ll stop seeing them if this goodwill is abused,” said a spokesperson for Abta, the travel association, in response to the findings.

Earlier this year, a survey of airline staff in 83 countries revealed that smartly-dressed, single men in their thirties are most likely to get a free upgrade on a flight , while women in their late teens wearing revealing clothing and travelling as a group would be the least likely to receive one.

The staff survey also revealed that 82 per cent were more inclined to give an upgrade to passengers who are friendly and polite, while 72 per cent were more likely to upgrade a passenger flying alone. Sixty-five per cent were more likely to upgrade a passenger with an injury.

Telegraph Travel examined airline upgrades for its Travel Truths column earlier this year. A number of carriers said the best bet would be to join the airline’s frequent flyer scheme.

“It is sometimes necessary to upgrade customers,” said a BA spokesman. “This is rare and will normally apply to frequent flyers who are members of our loyalty programme first."

A spokesman for Lufthansa said: “Passengers who paid more for their tickets are more likely to be upgraded than passengers who bought a discounted ticket. The frequent flier program status is also taken into account."

They added that “it never hurts to ask” for an upgrade at the check-in desk, but said having a genuine reason, such as being exceptionally tall, pregnant, or even celebrating a honeymoon, birthday, or anniversary, “would certainly improve your chances”.

Several airlines also confirmed that the majority of upgrades are offered for “operational reasons”, such as when the economy class cabin is full or oversold, but the premium cabins are not. Therefore travelling on a busy route, where this is more likely to occur, will help. Flights to beach resorts during the school holidays, when the majority of fellow passengers will be families, are also a good bet.