Legal action was threatened on Thursday against a school district in Missouri, after it was accused of discrimination for its policy banning same-sex dates for students attending school proms.

The Southern Poverty Law Center (SPLC) on Thursday accused the Scott County Central School District in Sikeston, of discriminating, and wrote that the district had until 25 February to revise the policy banning same-sex couples, or face potential legal action.

The school district has one elementary school, and one high school, which serve 330 students, combined.

According to the SPLC’s letter, Stacey Dawson, of Scott County Central High School asked if he could take his boyfriend to his prom on 20 April, but was told that the district’s policy prohibits same-sex couples.

The policy states that students “will be permitted to invite one guest, girls invite boys and boys invite girls.”

The SPLC alleges that the student said the school board had refused to change the policy.

SPLC attorney Alesdair Ittelson said the prom policy is “blatantly discriminatory and in violation of (the student’s) constitutional rights.”

“This unlawful policy reminds us that anti-gay sentiment still serves as a platform for schools to deny the rights of same-sex couples,” Mr Ittelson said in a statement reports KansasCity.

Mr Lawson said his prom “is an important milestone in high school, and I would be devastated if I’m not allowed to attend prom with my boyfriend.”

“It isn’t fair that a school can randomly disregard students’ rights because it doesn’t agree with who you want to take to prom,” he continued.

The letter from the SPLC cites a US Supreme Court ruling on Tinker v Des Moines Independent Community School District, which said the Iowa case protected the student’s right to free expression.

It also makes reference to a Mississippi lawsuit in which a federal court ruled that a female student attending a prom with a same-sex date “falls squarely within the purview of the First Amendment”.

It goes on to mention a 1980 Rhode Island case, following which a school was made to pay $116,000 for denying a student’s right to bring a same-sex date to a school dance.