Jet2, Ryanair, TUI, and Easyjet passengers could be turned away at the gate this summer for a surprising reason: their choice of clothing. An airline worker with years of experience has spilled the beans on why certain outfits might result in holidaymakers being barred from boarding their flights.

Mary Jo Manzanares, who has penned articles for CNN Travel and boasts 33 years as a flight attendant, has explained the rationale behind the strict dress code enforced by airlines. In her discussion with CNN Travel, she highlighted the importance of addressing any potential issues before takeoff, stating: "You've got to make your priority resolving things on the ground, making sure that there is no aggression. When you go to 30,000 feet, you may [have] passenger conversation or banter or inappropriate comments between passengers, add in a little alcohol, and you may be making an unscheduled landing. And no one wants that."

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A flight attendant also shared with The Sun: "We're well within our rights to prevent people getting on the flight and it's used frequently for people who aren't dressed in a way we would deem to be acceptable."

For those planning to fly with Jet2, Ryanair, TUI, or Easyjet, consider this a heads-up: attire matters. The flight attendant warned: "There are some obvious examples here, including t-shirts with swear words or offensive logos on them, which people are regularly asked to cover up, or remove, before they get on board."

While most airlines don't provide official dress code guidelines, it's generally a good idea to avoid wearing dirty or torn clothes, overly casual outfits, or any clothing with potentially offensive slogans or rude language. While some airlines are fine with passengers wearing flip-flops, others may not allow 'beach attire' on board.

It's also important to note that if a country has specific laws or local customs regarding clothing, airlines may expect passengers to respect these rules before boarding.