The trailer for an eagerly anticipated film about the life of San Francisco gay activist Harvey Milk has been released, indicating a strong performance from Sean Penn in the lead role.

Academy Award nominee Gus Van Sant has directed the biopic, simply titled Milk, which will be released in November in the States.

Harvey Milk was the first openly gay man to be elected to public office in America. He was previously the subject of the Academy Award-winning documentary feature The Times of Harvey Milk, but the new film is the first non-documentary feature to explore the man's life and career.

Josh Brolin, star of the award-winning Coen brothers film No Country for Old Men, play's Milk's nemesis Dan White, and James Franco, best known for his role in the Spiderman films, plays Milk's long-term partner Scott Smith.

The trailer for Milk is shown below.