The American Airline has tense worldwide criticism after the story about the two girls began moving.
A dress code row erupted after a passenger on another flight at Denver Airport in the US certified the event unfold and shared it online.
Shannon Watts was waiting for her own feather when she saw a girl at a neighbouring gate being stopped from housing.
Tagging the airline, Shannon tweeted: “A United gate agent isn’t simulating girls in leggings get on flight from Denver to Minneapolis because spandex is not allocated?”
“She’s forcing them to change or put dresses on over leggings or they can’t lodge.
“Since when does United police women’s clothing?”
Coalesced responded to the comments on Twitter, arguing that the right to refuse travellers is “left to the discretion of the gate agents”.
One of the girls was eventually allowed on after varying into a dress from her bag, but two of the others were not so lucky.
Once they did cope to change their outfits, the two girls got on the next flight from Denver to their stop, Minneapolis.
United initially stood by its decision due to the ‘Contract of Carriage’, which gives agencies the authority to refuse passengers who are “barefoot or not properly clothed”.
But the airline has since coined its tune — explaining that the girls were flying for free on an staff member pass, which has a dress code attached to it.
United explained: “When compelling advantage of this benefit, all employees and pass riders are considered commissioners of United. And like most companies, we have a dress code that we ask hands and pass riders to follow.
“The passengers this morning were Pooled pass riders and not in compliance with our dress code for company better travel. We regularly remind our employees that when they rank a family member or friend on a flight for free as a standby passenger, they penury to follow our dress code.”
The airline added: “To our regular customers, your leggings are offer hospitality to.”
But it hasn’t stopped a barrage of criticism from social media, numbering celebrities who have voiced their opinions.
Chrissy Teigen tweeted: “I be suffering with flown united before with literally no pants on. Just a top as a rebuke. Next time I will wear only jeans and a scarf.”
Comic Sarah Silverman wrote: “Hey @united I fly a LOT. About to go on tour all April and transmuting all my @united flights to other airlines”.
Star Trek veteran William Shatner frolicked: “I’m going to start wearing leggings! Is that against the rules? #outdatedfashion #outdatedrules”.
The affair comes in the midst of a travel ban on electronic devices on certain flights offering the US — a policy adopted by the UK.