Brits en-route to Mexico were left 'distraught' when they discovered mid-flight that travel restrictions had been changed.
The UK government announced yesterday (4 August) that the Central American country was being moved from the amber list to the red list.
From 4am on Sunday (8 August), holidaymakers returning to the UK from Mexico will have to isolate in a hotel for 10 days.
This means that Brits must decide whether to potentially fork out over £6,000 for a flight back to the UK before the cut-off or over £2,000 per person to isolate in a hotel upon their return after Sunday.
Claire, 30, from south London, was one of those who discovered mid-flight that restrictions were being changed, branding the move 'crazy'.
She said: "I had access to the Wifi so I found out in mid-air.
"I just wanted to grab the tannoy and tell everyone because I could see all these families looking forward to their holiday and it was obvious they didn't know.
"It's crazy the lack of notice. I had no inkling Mexico was about to go on the red list."
According to reports, the only direct flight from Mexico City to London before Sunday will set travellers back an eye-watering £6,878.
As a result of the changes, a young couple have had to cut short their honeymoon in Mexico from two weeks to two days.
Joe Coward, from London, discovered the new restrictions after landing in Mexico early this morning (5 August) and quickly booked a new return flight.
The 29-year-old student said everything had been 'ruined' and he could end up thousands of pounds out of pocket.
"Basically we touched down to find that our two-week honeymoon, which had already been rearranged several times, was going to be a two-day visit," he said.
"We've arranged a flight for tomorrow and will be spending today getting ready to turn right around and go home.
"We feel extremely angry at the Government's incompetent handling of international travel rules during this crisis, and incredibly sad and frustrated that the time that should've been spent enjoying being newlyweds has been ruined."
And they aren't alone.
Ayo Faley is a call handler for NHS Test and Trace in London and also landed in Cancun earlier today.
But unlike Joe, she is staying for the duration of her holiday as planned but says she is 'absolutely distraught' and will not be able to work when she returns home on 11 August.
The 24-year-old said: "I only found out (travel restrictions had changed) the minute I was able to connect to wifi at the airport... I went into a state of panic."
"(I tried) to locate other Brits and see whether they knew and what their next plan of action was... you could see the look of confusion, fear and regret all in their faces.
"I am absolutely distraught... I've decided to just stay and enjoy the time here... I'll just have to face the consequences when I arrive."
Transport Secretary Grant Shapps claimed on Thursday the current traffic light system means holidaymakers can travel abroad without 'looking over their shoulders' in fear of being caught out by changing rules.