OLYMPIA, Wash. (AP) – The state Supreme Court expects to issue its long-awaited ruling this week in a case challenging the state’s same-sex marriage ban, justices announced.

The news surprised those who expected a decision after the fall elections, and sent supporters and opponents of same-sex marriage rushing to prepare for the ruling.

If the state’s 1998 Defense of Marriage Act is overturned, Washington would become the second state after Massachusetts to allow gay and lesbian couples to wed.

Sleep will be difficult while awaiting the court’s decision, said David Shull, 47, a plaintiff in the case.

“After 16 months, it’s just stunning,” Shull said in a phone interview from his south Seattle home. “But it’s thrilling, it really is exciting.”

The court’s short announcement, posted on its Web site July 25, gave no indication of how it might rule.

Court officials did say that concurrences and dissents would accompany the majority decision, raising the possibility of several separate opinions from the nine justices.

The 38 plaintiffs in the case – 19 same-sex couples seeking to marry – challenged the constitutionality of the state law limiting marriage to heterosexual couples.

In 2004, judges in King and Thurston counties overturned the marriage law, citing the state constitution’s “privileges and immunities” section. The cases were consolidated for Supreme Court review.

In arguments before the Supreme Court in March 2005, plaintiffs’ attorneys argued the same-sex marriage ban violates a constitutional prohibition against granting privileges to one group of citizens and not another. They also argued the ban violates the state’s Equal Rights Amendment.

Attorneys defending the marriage law said the state has a rational reason for limiting marriage to heterosexual couples, because the state has an interest in regulating relationships that produce children.

Same-sex marriage supporters were cautiously optimistic they would prevail.

“We have lots of hopes and reasons to think the state is ready to embrace marriage for same-sex couples,” said Jennifer Pizer, an attorney on the case for Lambda Legal.

One leading opponent in the case, Gary Randall, president of the conservative Faith and Freedom Network, said same-sex marriage foes generally expect to lose, despite polling he said shows opposition to same-sex marriage in the state.

“That would be a very unpopular decision among the faith community, both among Protestants and Catholics,” Randall said.

Speculation about the timing of the court’s ruling has run rampant in the months since the case was argued, with many believing justices would wait until after the election cycle to issue their ruling. Three of the court’s justices are running for new terms this fall.

But last week, Justice Susan Owens told The Associated Press the ruling would come before the state’s Sept. 19 primary.

Rep. Ed Murray, the state’s senior openly gay lawmaker, said he had no criticism of the long wait.

Murray, D-Seattle, added that he and his longtime partner, Michael Shiosaki, “will either plan on getting married on our anniversary, Aug. 10, in a small ceremony, or we will be disappointed.”

“We are personally on a bit of a roller coaster, but hopeful,” Murray said.