Constance McMillen, the Mississippi teenager barred from going to prom with her girlfriend, is to attend a Pride reception at the White House this evening.

She is also set to be a grand marshall at New York Pride on Sunday.

Tonight’s reception was announced last week. While the guestlist has been kept under wraps, it is expected the event will have a focus on young people.

President Barack Obama is to attend and make a short speech.

Ms McMillen will also lead New York Pride.

Speaking to the New York Daily News, she said she did not know what to wear to lead the march.

She said: “There was a girl at school who wore a t-shirt that said, ‘Thanks Constance, for ruining the prom’.

“It was ridiculous. Maybe I should wear a T-shirt that says, ‘You’re welcome’ on one side and ‘Lesbian who ruined the prom’ on the other. What do you think?”

The 18-year-old student made headlines around the world earlier this year when she was barred from attending her prom with her girlfriend.

Ms McMillen wanted to wear a tuxedo but was told she and her girlfriend would have to wear dresses and would not be permitted to dance together or show each other affection.

When she complained to the American Civil Liberties Union, Itawamba Agricultural High School cancelled the whole event.

Ms McMillen lobbied the school and students to put on an inclusive prom. She was then directed to a “fake” event with only a handful of students, while the majority of her peers enjoyed a private prom.