A spokeswoman for Jet2.com said told Sky News: "Our pricing, as is common practice in the travel industry, is based on the principle of supply and demand."
"As supply reduces, an inevitable consequence is that prices increase. However, we are looking at adding more supply (flights and seats) to help customers at this time."
Angela Mills, a vacationer, told the BBC that a flight from Glasgow, Scotland to Rhodes, Greece, was £1,000 on Tuesday, up from £280 on Sunday. She did not say which airlines she was looking at.
Related: 20 best airlines in the world
20 best airlines in the world
20 best airlines in the world
20. Hong Kong Airlines
Previous rank: 24
Why it's awesome: Hong Kong Airlines has been on an impressive growth streak over the past couple of years. Not only has it rapidly expanded its global network, the carrier has also worked to improve service and product. Hong Kong Airlines is a subsidiary of China's HNA Group.
Why it's awesome: Royal Dutch KLM is considered the oldest continuously operating airline in the world. Based out of Amsterdam's Schiphol Airport, KLM is famous for its bright blue livery and Dutch house liquor bottle figurines. The airline is one half of the Franco-Dutch conglomerate Air France-KLM.
KLM also took home the prize for Best Business Class Seat in Europe.
Why it's awesome: Turkish Airlines is the flag carrier of Turkey and has its main hub at Istanbul's Ataturk Airport. The airline, with its ability to fly to over 100 countries and over 200 cities worldwide, hopes to turn its home base into a global transit hub.
Even though political unrest and security concerns have made life more complicated for Turkish Airlines, the carrier's high-quality service, and product offerings remain unchanged.
Turkish is a member of Star Alliance and had won the Skytrax award for Best Airline in Europe six years in a row before losing the title to Lufthansa last year.
(Photo by Vladimir Shtanko/Anadolu Agency/Getty Images)
17. Air New Zealand
Previous rank: 19
Why it's awesome: In 2018, Air New Zealand reclaimed the titles of World's Best Premium Economy Class and World's Best Premium Economy Seat from Aussie rival Qantas, the Kiwi carrier remains one of the industry's finest long-haul carriers.
In economy class, families can opt for the airlines innovative Skycouch that transforms a bank of three economy seats into a flat activity area.
Why it's awesome: Austrian Airlines has overcome a series of labor disputes in recent years, with its high level of service intact. In 2018, the Lufthansa-owned carrier, once again, took home the prize for Best Airline Staff Service in Europe. The Austrian flag carrier boasts a fleet of newly renovated long-haul Boeing 767-300ER and 777-200 jets flying out of its base in Vienna.
Economy fliers gave the Star Alliance member high marks for its efficient and effective service, as well as for the wealth of onboard dining and entertainment options.
Why it's awesome: Etihad Airways, based in Abu Dhabi, is the flag carrier of the United Arab Emirates, with its Airbus and Boeing fleet traveling to about 100 destinations. The airline has become famous for its trademark Residence flying apartments as well as its plush first-class and business-class suites.
Why it's awesome: Japan's flag carrier is one of the most respected airlines in the world. Reviewers on Skytrax praised Japan's second-largest airline for its attentive service, well-coordinated ground staff, and comfortable cabin.
For 2018, Japan Airlines once again won the award for Best Economy Class Airline Seat.
(Photo credit should read TORU YAMANAKA/AFP/Getty Images)
12. Swiss International Air Lines
Previous rank: 14
Why it's awesome: Swiss International Air Lines emerged in 2002 from the remnants of the now defunct Swissair and is now a member of the Lufthansa corporate family. In 2016, the Basel-based carrier became the first in the world to operate the next generation Bombardier C-Series airliner.
Though some fliers found economy seat comfort to be lacking, most praised the cabin crew for its friendly service and the airline for its wide assortment of complimentary adult beverages.
Plus, the complimentary Swiss chocolate is always a fan favorite.
Why it's awesome: Even with strong competition from Virgin Australia, Qantas has been resurgent over the past couple of years. The airline received praise for its strong customer service and in-flight entertainment. And then there's Qantas' calling card — it has a fatality-free safety record in the jet era.
Why it's awesome: Thai Airways has long been an industry leader for quality service, so it's no surprise to find the Thai national carrier high up on the list. Though its most heralded products are its business and first-class services, fliers found its economy seats to be of high quality as well.
Economy fliers on Skytrax also noted the crew's friendly demeanor and delectable dining options.
In 2018, Thai Airways once again took home the award for the World's Best Economy Class, the World's Best Economy Class Onboard Catering, and the World's Best Airline Spa Facilities.
(Photo by C. V. Grinsven/SOPA Images/LightRocket via Getty Images)
9. Garuda Indonesia
Previous rank: 10
Why it's awesome: Garuda Indonesia has experienced a dramatic turnaround in recent years. The Indonesia flag carrier has undertaken extensive fleet renewal and service improvement measures to regain the trust of both fliers and safety regulators.
Economy fliers have raved about the airline's comfortable seats and selection of Southeast Asian cuisine.
In 2018, Garuda's flight attendants took home the award for the World's Best Cabin Crew for the third year in a row.
Why it's awesome: Founded in 1993, Hainan is the only Chinese airline to hold the coveted Skytrax five-star rating. In four short years, the airline surged from 22nd place all the way into the top 10. With a brand-new fleet of more than 160 Boeing and Airbus jets, Hainan is expanding rapidly throughout Asia, Europe, and Australia.
Reviewers on Skytrax praised the airline for its attentive service and quality business class accommodations.
Hainan also won the awards for Best Airline in China and Best Airline Cabin Crew in China.
Why it's awesome: Although Cathay Pacific, based in Hong Kong, fell back one spot from last year, the airline still retains its place as one of the most respected carriers from the Pacific rim. With a fleet of long-range Boeing 777-300ER jets and a business strategy centered on offering a high frequency of flights, Cathay is one of the finest flying experiences in Asia.
Skytrax reviewers gave the airline high marks for seat comfort, service quality, and in-flight entertainment.
Why it's awesome: Taiwan's EVA Air (pronounced ee-vee-ay) was founded in 1989 and is an offshoot of global container-shipping giant Evergreen Group. The Taipei-based carrier has grown immensely in the past two decades and now operates a large fleet of Airbus and Boeing wide-body jets. The airline is credited with pioneering the "premium economy" cabin.
(Photo by Fabrizio Gandolfo/SOPA Images/LightRocket via Getty Images)
Previous rank: 4
Why it's awesome: Over the past 30 years, Dubai's Emirates has developed into one of the world's premier long-haul carriers. Operating almost exclusively through its palatial hub at Dubai International Airport, the carrier boasts the world's largest fleet of Airbus A380 superjumbos and Boeing 777 wide-body jets.
Emirates' state-of-the-art in-flight entertainment system includes a wide selection of video and music options on demand, and even allows for live television and sporting events on its "ice" entertainment system-equipped aircraft. In fact, Emirates has taken home Skytrax's award for Best In-Flight Entertainment 14 years running.
Why it's awesome: All Nippon Airways continues its march towards the top of the rankings. ANA is the largest international carrier in Japan and home to one of the world's largest fleets of Boeing 787 Dreamliners. ANA drew high praise from Skytrax reviewers across the board for cleanliness, service, and safety. Many of its planes feature slide-forward-style reclining seats that increase overall privacy, as well as power and USB outlets even in economy.
ANA also won Best Airline Staff in Asia and Best Cabin Crew in Japan.
(Photo by Fabrizio Gandolfo/SOPA Images/LightRocket via Getty Images)
2. Qatar Airways
Previous rank: 1
Why it's awesome: Qatar Airways falls back one spot to second.
The Doha-based airline received praise from reviewers for its seat comfort and in-flight entertainment. In fact, the airline boasts the second best in-flight entertainment system and economy class offering in the world The airline links over 150 destinations across the globe and is expanding its fleet to include the latest generation of long-haul airliners including the Boeing 787 Dreamliner and Airbus A350.
Qatar also took home the award for Best Airline in the Middle East, World's Best Business Class, and Best First Class Airline Lounge.
Why it's awesome: Singapore's standout service makes for a famously pleasant journey during which flight attendants are trained to treat customers with extreme care and respect. Personal TVs with plenty of entertainment options and hot towels served before take-off are just some of the economy perks.
A spokesperson for British Airways told Sky News that the flight prices are based on supply and demand, and denied targeting Thomas Cook routes specifically.
The Sun also reported on a TUI airline return flight from Scotland to the Canary Islands that increased from £320 to £620.
A TUI spokesman told Business Insider: "TUI uses a dynamic pricing model which means that our prices can go up or down. There are many variables which have to be taken in to account including peak dates of travel, regional airport differences and which channel our customers book through."
The Sun also reported on a Ryanair flight from England to Spain that increased from £113 to £226. Business Insider has contacted Ryanair about increased flight prices.
Experts say the price increases are inevitable
John Strickland, an airline analyst at JLS Consulting, told the BBC: "People aren't sitting there rubbing their hands with glee. If sales come in rapidly on popular routes then prices go up."
He said: "When a particular route ceases to operate, prices do indeed increase substantially, but this generally occurs over a matter of weeks and months. I expect it will be similar in this case as the additional demand will increase prices on other carriers."
Lisa Tyndall, a spokeswoman for flight comparison website Skyscanner, told the newspaper: "We typically see prices increase for key routes when an airline ceases trading, before reverting back again soon after."
Most people now looking to book new flights are those who have had their future trips ruined.
Those who booked package holidays through Thomas Cook should eventually get a refund, but this is not the case for those who only booked flights through the company.
The UK government is flying home the 15o,ooo British people now stuck abroad.
Thomas Cook's biggest routes were places like Greece, Italy, Turkey, Spain, and the Caribbean. It also offers package holidays in the winter, which could mean that winter travel prices are also affected.