Making its strongest declaration in support of gay rights, US President Barack Obama's administration has asked the Supreme Court to overturn California's same-sex marriage ban and turn a sceptical eye on similar prohibitions across the country.
"Throughout history, we have seen the unjust consequences of decisions and policies rooted in discrimination," Attorney General Eric Holder said.
"The issues before the Supreme Court in this case and the Defence of Marriage Act case are not just important to the tens of thousands Americans who are being denied equal benefits and rights under our laws, but to our Nation as a whole," he said in a statement.
However the Obama administration fell short of declaring its support for a constitutional right to gay marriage that would immediately apply in all 50 states, as was being urged by many.
In its submission before the Supreme Court, the Obama administration said by depriving same sex couples of the right to marry denies them the dignity respect and stature accorded similarly situated opposite sex couples under the State Law.
Separately, the California's Indian-American Attorney General Kamala Harris, also filed a friend-of-the-court brief in the United States Supreme Court arguing that Proposition 8 is unconstitutional and the initiative's sponsors do not have the right to claim to represent the interests of California by defending the law in federal court.
"Equal protection under the law is a bedrock of our Constitution and fulfils our nation's binding principle that all people are created equal and should live free of discrimination," she said.
"I look forward to the day when all Californians are granted their full civil rights and can marry the person they love," she added.
In August 2010, a federal district court invalidated Proposition 8 on the grounds that it violated the equal protection guarantee of the Fourteenth Amendment of the United States Constitution by taking away the right of same-sex couples to marry, without a sufficient governmental interest.
Governor Jerry Brown and Attorney General Harris both refused to defend Proposition 8 on the basis that the law is unconstitutional.