A mum was told she would have to pay more than £100 extra to ensure she can next to her three-year-old son on a 10-hour flight to America.
Joanne Curren, 44, paid for flights for her and her boy, Noah, to visit her parents who live in California.
But Thomas Cook told Joanne she will have to pay between £25 and £35 more per seat to ensure she is in the seat next to Noah.
Mother-of-one Joanne, from Sheffield, South Yorkshire, travels to California to visit her parents, who are in their 80s, every couple of years.
She was planning a two-week trip for her and Noah for the end of July.
The flights from Manchester to Los Angeles International Airport cost around £1,600.
But Joanne was shocked to discover she would have to pay a further £140 extra to ensure she sits next to Noah – who will have turned four when they travel.
Joanne, who works in a school kitchen, said: “My parents live in California so last year was the first year just me and my son went to America.
“We went by BA and automatically sat together without paying extra or pre-booking.
“Then this time it was only through a conversation I found out the seats had been separated, I thought ‘that can’t be right’.
“I went in to Thomas Cook in Rotherham and they said that if other people have booked their tickets I could be a row in front or a row behind or on the same row, but not next to him.
“I didn’t pre-book a specific seat because I don’t mind where we sit, as long as it’s together.
“But he will have just turned four when we go – he won’t stay in his seat if I’m not next to him.”
Joanne says she is concerned if there is turbulence during the long journey to the US there are no safety measures in place if she is not next to the youngster.
She added: “What I really want to know is what will Thomas Cook do about the safety aspect.
“Surely the plane won’t be able to take off if he is getting out of his seat?
“That would mean they would get fined if it has to stay on the runway.
“What if there is turbulence over the Atlantic? How will that be dealt with, will the person who is sitting next to him have to fit his mask in the event of an emergency?
“Are they going to be happy sitting next to a four-year-old for ten hours? Are they going to be happy for me to reach across the aisle to help my child?
“He is not a confident enough kid to be able to sit on his own so he won’t sit in his seat, he’ll be running up and down the aisle. He’ll probably be kicking the seat in front as well.
“Will the person who sits next to him be DBS (Disclosure and Barring Service) checked as he will be sitting next to strangers for ten hours over night.
“I feel like they are holding people to ransom so pay extra just to sit next to family members.
“Disabled people automatically get seated next to carers, they don’t have to pay extra – young children should be in the same category.
“It would be fine if he was seven or eight, but he’s only four.”
In reply to Joanne’s concerns, a Thomas Cook representative said on Facebook that the company do their best to sit families together but cannot guarentee so.
The message read: “We always try to sit families together where possible.
“However, due to other customers pre-booking seats, we aren’t able to guarantee that there will be seats available together at check-in.
“The only way we can ensure you’re sat together would be by pre-booking your seats.
“We would do everything we can to put you together. Once the plane is booked up and there’s not enough room to seat all the family members together, the only option would be for cabin crew to politely ask people who’ve booked their seats to move.
“However, passengers who have pre-booked their seats can refuse. The best and only way to ensure you are all sat together is pre-book your seats so that this doesn’t happen.”