A Texas school has relented and allowed a trans teen to wear a dress to the prom.

In a letter to Senior High School’s Principal Ullrich, the American Civil Liberties Union said George ‘Tony’ Zamazal had a legal right to wear feminine attire.

Zamazal had said she recently started feeling more comfortable in girl’s clothes, and started using female pronouns to describe herself.

‘[The principal] told me it just wasn’t in the dress code. Women wore dresses, and men wore tuxedos,’ Zamazal said.

‘It’s not okay to just tell people they can’t be the way that they are. It’s not just a choice of the way you look, it’s more of who you are.’

When the assistant principal told Zamazal it would have to be a ‘community decision’ to let her wear a dress, the ACLU informed the school she has the right under the US constitution to peacefully express her gender identity.

In the letter, they said: ‘Surely other students at Spring High School are not expected to obtain the Board’s consent to wear dresses to prom.

‘Requiring Board approval would single out Tony’s protected speech for special burdens based on the content of her speech in a manner that would violate Tony’s First Amendment rights.’

The school district said she must still adhere to its dress code, and ‘Tony will be held to the same standard that female students are held to regarding these articles of clothing.’

Zamazal is happy with that, telling ABC News: ‘To me it actually means I’m actually going to be able to go to prom as who I really am.’

The teen’s case is the latest challenge to high school prom regulations across the United States.

In Missouri, gay teen Stacey Dawson was told he hoped to take his boyfriend as his senior prom date. It was only after a legal challenge that the school’s superintendent reportedly agreed to revise the policy banning same-sex prom dates.

Back in 2010, Constance McMillen was banned from bringing her female date and wearing a tuxedo.

After the 18-year-old complained, the Mississippi school then cancelled the prom and encouraged parents to organize a private prom and not invite the gay teen.

After a lengthy lawsuit, the school was later ordered to pay $35,000 (£22.5k, â‚¬26.1k) in damages to McMillen.