The Obama administration on Thursday filed a brief urging the U.S. Supreme Court to find Proposition 8, California's gay marriage ban, in violation of the U.S. Constitution.

In the brief written by Solicitor General Donald Verrilli Jr., the administration stops short of calling on the court to strike down marriage bans nationwide.

“California law provides to same-sex couples registered as domestic partners all the legal incidents of marriage, but it nonetheless denies them the designation of marriage allowed to their opposite-sex counterparts. Particularly in those circumstances, the exclusion of gay and lesbian couples from marriage does not substantially further any important governmental interest. Proposition 8 thus violates equal protection.”

(Read the full brief.)

As late as last week, President Barack Obama stated that he was unsure whether a brief would be filed in the case, known as Hollingsworth v. Perry.

NPR noted that the president made the decision to file the brief possibly as late as Wednesday.

Attorney General Eric Holder commented on the brief in a statement: “In our filing today in Hollingsworth v. Perry, the government seeks to vindicate the defining constitutional ideal of equal treatment under the law. Throughout history, we have seen the unjust consequences of decisions and policies rooted in discrimination. The issues before the Supreme Court in this case and the Defense of Marriage Act case are not just important to the tens of thousands of Americans who are being denied equal benefits and rights under our laws, but to our Nation as a whole.”

Among those applauding the administration is Chad Griffin, president of the Human Rights Campaign (HRC), the nation's largest gay rights advocate. Griffin is a co-founder of the American Foundation for Equal Rights (AFER), the group formed specifically to support the legal challenge to Prop 8.

“In his second inaugural address last month, the president said our journey is not complete until 'the love we commit to one another' is equal as well. His words inspired a nation, and his amicus brief puts them into concrete action,” Griffin said.

Evan Wolfson, founder and president of Freedom to Marry, added that the administration's brief provides “the legal roadmap, calling on the Supreme Court to uphold the Constitution's command of equal protection under the law.”

“It is time for the justices, like our president and the majority of Americans, to embrace the freedom to marry and get our country on the right side of history,” he added.

The court will hear oral arguments in the case later this month and is expected to deliver a ruling in June.