Rival airlines are hiking prices by as much as 400% after Thomas Cook collapsed

• Airfare prices for routes previously served by travel company Thomas Cook are surging in the wake of its collapse.
• Travellers found tickets with rival airlines like Jet2, British Airways, Ryanair, and TUI to have gone up as much as 400% since Thomas Cook abruptly stopped operations on Monday.
• The collapse left 600,000 people stranded around the world, and many with now-worthless bookings for future flights.
• Airlines responded by saying that their prices are determined by market forces. Industry analysts say that increases are the inevitable consequence of a provider collapsing.
• Visit Business Insider's homepage for more stories.

Airlines are being accused of inflating their flight prices by as much as 400% after the collapse of UK airline Thomas Cook.

Travelers booking flights since the company's collapse on Monday say that prices have soared. Thomas Cook ran dozens of flights a day, and its collapse left 600,000 stranded around the world.

Customers with future bookings have found their trips cancelled, and must rebook with rival operators if they still want to travel.

One traveler said on Monday that the cost of a flight with British budget airline Jet2 had almost doubled within an hour of Thomas Cook's collapse:

Another said that a flight had tripped, from £47 to £145:

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."

Read more: Passengers share vacation disasters from the Thomas Cook collapse, including a ruined $41,000 wedding and 'being held hostage' by angry staff at a Tunisian hotel

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.

The UK's The Sun newspaper reported that one passenger found a flight with British Airways from London to Orlando, Florida, was £1,978 after the collapse, up from £437 before.

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.

Read more: Roughly 600,000 travelers are stranded around the world after the British travel provider Thomas Cook declares bankruptcy

The newspaper also reported on a TUI airline return flight from Scotland to the Canary Islands that increased from £320 to £620, and a Ryanair flight from England to Spain that increased from £113 to £226. Business Insider has contacted Ryanair and TUI 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."

Jack Sheldon, founder of flight price website Jack's Flight Club, told the UK's Guardian newspaper that this always happens.

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."

Read more: The UK expects to spend £100 million flying back stranded Thomas Cook passengers, which is only £50 million less than bailing out the company

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."

Travellers have been sharing how the collapse has ruined their plans, including people who had expected to fly for their weddings.

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.

• Read more about the collapse of Thomas Cook:

• Stranded Thomas Cook customers say a single piece of paper taped to their hotel's reception is the only contact they've had from the collapsed tour operator

• The UK expects to spend £100 million flying back stranded Thomas Cook passengers, which is only £50 million less than bailing out the company

• Boris Johnson says he refused £150 million bailout for Thomas Cook because it risked 'moral hazard' for other firms

• Hedge funds could reap as much as $250 million from the collapse of British tour operator Thomas Cook

• A German subsidiary of bankrupt Thomas Cook will be kept alive with a German loan

• A Thomas Cook flight attendant says she only learned that the company collapsed and she lost her job on Facebook