TUI has issued a travel warning to holidaymakers after being forced to cancel a number of flights over the weekend.
Thousands of Brits faced huge queues, cancelled flights and missed holidays due to the problems across the UK.
Some families had to wait more than 24 hours at the airport due to delays with TUI, while some said they were told their holidays were cancelled with just a few hours notice.
The tour operator has apologized for the recent problems and said they were doing "everything we can to limit any flight delays."
However, they have since warned passengers to not arrive at the airport too early, saying this can cause more queues.
The TUI website states: "We’d like to remind customers not to arrive at the airport too far in advance of their flight, as this can contribute to terminal queueing delays.
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"Standard check-in opens at least two and a half hours before departure time for short and mid-haul flights, and at least three and a half hours before departure for long-haul flights."
They also explained how passengers can drop off their bags the day before at some airports, for any Brits who are staying over before their flight.
It wasn't just TUI causing chaos for holidaymakers - easyJet was also forced to cancel hundreds of flights.
The airline confirmed that more than 200 flights will be cancelled over the next 10 days - just days after an IT glitch grounded hundreds of flights.
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A mum has told of her "nightmare" easyJet experience after her family's flight to Tenerife was cancelled twice.
She said they were even forced to sleep on the floor at Gatwick Airport after spending £2,500 on their holiday to celebrate their family's wedding anniversary and birthdays.
Passengers said they endured a second day of chaos at major UK airports across the weekend with travellers in Bristol complaining about delays and staffing issues.
One person tweeted: "Bristol Zoo, sorry airport, was the same for the Mrs on Friday. She made her flight only because it was delayed.
Another wrote: "Arrived at Bristol airport at 11AM for our 2PM flight to Gran Canaria to find out it has been delayed for seven hours. Not scheduled to leave until 20.55."
And on Saturday, some TUI customers were forced to wait four hours for a pilot to show up for a flight from Manchester to Kos - something the company has since apologised for.
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