WASHINGTON (AP) — The Obama administration is considering urging the Supreme Court to overturn California’s ban on gay marriage — a move that could have a far-reaching impact on same-sex couples across the country.

The administration faces heightened expectations from gay rights supporters after President Barack Obama, who only last year came out with his support on the issue, has become far more vocal on gay rights in his second term.

His administration has one week to file a friend-of-the-court brief with the justices outlining its opinion on the California ban, known as Proposition 8. While an administration brief alone is unlikely to sway the high court, the government’s opinion does carry weight with the justices.

Opponents of the Proposition 8 ban believe the president signaled his intention to file a brief when he declared in last month’s inaugural address that gays and lesbians must be “treated like anyone else under the law.”

An administration official said Obama, a former constitutional law professor, was not foreshadowing any legal action in his remarks and was simply restating his personal belief in the right of gays and lesbians to marry, though the official said the administration was considering filing a brief.

Solicitor General Donald Verrilli is consulting with the White House on the matter, according to a senior administration official, who spoke only on condition of anonymity because the official was not authorized to address the private deliberations publicly.

The Proposition 8 ballot initiative was approved by California voters in 2008 in response to a state Supreme Court decision that had allowed gay marriage. Twenty-nine other states have constitutional amendments banning gay marriage, while nine states and Washington, D.C., recognize same-sex marriage.

Public opinion has shifted in support of gay marriage in recent years. In May 2008, Gallup found that 56 percent of Americans felt same-sex marriages should not be recognized by the law as valid. By November 2012, 53 percent felt they should be legally recognized.

While the Justice Department would make the filing, the president is almost certain to make the ultimate decision on whether to do so.

“I have to make sure that I’m not interjecting myself too much into this process, particularly when we’re not a party to the case,” Obama said Wednesday in an interview with San Francisco’s KGO-TV.

He said his personal view was that gay couples should have the same rights as straight couples and said his administration would do whatever it could to promote that principle.

Obama has a complicated history on gay marriage. As a presidential candidate in 2008, he opposed the California ban but didn’t endorse gay marriage. As he ran for re-election last year, he announced his personal support for same-sex marriage but said marriage was an issue that should be decided by the states, not the federal government.

To some, Obama’s broad call for gay rights during his Jan. 21 inaugural address was a sign that he now sees a federal role in defining marriage.

“Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law,” Obama said during his remarks on the west front of the Capitol. “For if we are truly created equal, than surely the love we commit to one another must be equal as well.”

Seeking to capitalize on growing public support for gay marriage, advocates are calling on the administration to file a broad brief not only asking the court to declare California’s ban unconstitutional but also urging the justices to make all state bans illegal.

“If they do make that argument and the court accepts it, the ramifications could be very sweeping,” said Richard Socarides, an attorney and advocate.

The administration could also file a narrower brief that would ask the court to issue a decision applying only to California. Or it could decide not to weigh in on the case at all.

The Supreme Court, which will take up the case on March 26, has several options for its eventual ruling. Among them:

— Uphold the state ban on gay marriage and say citizens of a state have the right to make that call.

— Endorse an appeals court ruling that would make same-sex marriage legal in California but apply only to that state.

— Issue a broader ruling that would apply to California and seven other states: Delaware, Hawaii, Illinois, Nevada, New Jersey, Oregon and Rhode Island. In those states, gay couples may join in civil unions that have all the benefits of marriage but may not be married.

— Rule that the Constitution forbids states from banning same-sex unions.

For weeks, supporters and opponents of Proposition 8 have been lobbying the administration to side with them.

Last month, Theodore Olson and David Boies, lawyers arguing for gay marriage, met with Verrilli and other government lawyers to urge the administration to file a brief in the case. A few days later, Charles Cooper, the lawyer defending Proposition 8, met with the solicitor general to ask the government to stay out of the case. Those kinds of meetings are typical in a high court case when the government is not a party and is not asked by the court to make its views known.

Boies and Chad Griffin, president of the advocacy group Human Rights Campaign, also had a meeting at the White House on the case.

Ahead of next week’s deadline, nearly two dozen states have filed briefs with the court asking the justices to uphold the California measure.

One day after the court hears the California case, the justices will hear arguments on another gay marriage case, this one involving provisions of the federal Defense of Marriage Act. The act defines marriage as between a man and a woman for the purpose of deciding who can receive a range of federal benefits.

The Obama administration abandoned its defense of the law in 2011 but continues to enforce it.

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Associated Press writers Julie Pace and Mark Sherman and News Survey Specialist Dennis Junius contributed to this report.

Copyright 2013 The Associated Press.