George Clooney - Clooney To Star In Black's Proposition 8 Play

Gay unions were made legal for the first time in California in 2008, but state legislation Proposition 8 made same-sex marriages illegal just six months after they were declared valid.

Several celebrities, including Sir Ian MCKellen, Lance Bass and Sir Elton John, were outraged at the reversal, and Milk screenwriter Black penned a stage play, entitled 8, about the controversy surrounding the bill.

Clooney has agreed to star in the Los Angeles production on 3 March (12) to benefit the the American Foundation for Equal Rights - and he's calling on lawmakers to overturn the ban on same-sex marriages.

He says, "It is astonishing that gay and lesbian Americans are still treated as second-class citizens. I am confident that, very soon, the laws of this nation will reflect the basic truth that gay and lesbian people - like all human beings - are born equal in dignity and rights."