A lesbian student in Indiana, US, has sued her school after she was banned from wearing a tuxedo at a prom.

The 17-year-old, who has not been named, does not wear dresses because she sees them as expressing a sexual identity she does not embrace, court filings said.

According to reports, Lebanon High School has a special dress code for prom that requires female students to wear a formal dress.

A lawsuit filed on the girl’s behalf by the American Civil Liberties Union of Indiana claims that the dress code policy deliberately discriminates against students based on gender and violates her free speech rights and the equal protection clause of the Constitution.

It also alleges that as the school receives federal funding, the policy violates federal law.

The student’s attorney has asked the federal court to issue an injunction that would require the school to let her wear the same formal attire to the prom as male students at the school.

Kent Frandsen, attorney for the Lebanon Community school district, told Associated Press that officials were considering letting the girl wear a pantsuit to the prom, adding that the school would follow the court’s ruling.

In December 2007, the Northern District Court of Indiana was told a high school violated a male pupil’s rights under the First Amendment of the US constitution by barring him from his prom for wearing a dress.

K K Logan, who studied at West Side High in Gary and was usually supported by the school in his clothing choices, was not allowed to enter the prom because he was not wearing a tuxedo.