The Gay and Lesbian Alliance Against Defamation (GLAAD) in America has launched a competition to create a thirty-second television advert advocating same-sex marriage.

Joan M. Garry, the organisation's executive director, said: "If you can translate your passion for fairness and equal protection for same-sex couples into 30 compelling seconds that counter the negative, discriminatory and fear-mongering tactics of the religious right, then we want to hear from you."

Amateur and professional filmmakers are invited to submit commercial spots to the organisation for consideration. They should speak to a mainstream audience and can be in any form, including live-action and animation, as long as the finished product is of broadcast quality. GLAAD will then air the advert in key markets across America over the summer and through the year.

Submissions should be in to GLAAD by May 11. Details are available on GLAAD.org.

The winning ad will be announced on June 5 at the GLAAD Media Awards in San Francisco. A panel of celebrity judges will choose the winning spot, including: producer Craig Zadan (Chicago), director Jane Anderson (Normal), writer/director Kevin Williamson (Scream), actor Judith Light (The Stones), director Paris Barclay (The West Wing), producer Bruce Cohen (American Beauty) and writer/actor Heather Juergensen (Kissing Jessica Stein), with more to be announced shortly.

Contest judge and Academy Award-winner Bruce Cohen said: "The contest is a great way to strike a chord with the public. Sharing images and stories of families, love and the desire for equality will put a human face on the struggles of lesbian, gay, bisexual and transgender people that everyone can relate to."