The bill introduced by Sen. Sharon Brown, R-Kennewick, would allow businesses the right to deny services or goods if they felt doing so was contrary to their "sincerely held religious beliefs, philosophical beliefs, or matters of conscience."
The measure would not apply to the denial of services to people under a protected class under federal law, such as race, religion or disability.
Brown said the measure seeks to protect people or religious organizations from legal persecution. "There's a glaring lack of protection for religion in state law," she said.
Also signing on to the bill were Sens. Janea Holmquist Newbry, Mike Hewitt, Jim Honeyford, Don Benton, Barbara Bailey, Mike Padden, John Braun, John Smith, Ann Rivers, and Linda Evans Parlette.
The bill has not yet been referred to a committee or scheduled for a public hearing, and is not likely to before the regular legislative session ends on Sunday. However, if a special session is called, as expected, the bill could be heard during that time.
Earlier this month, the American Civil Liberties Union in Washington state filed a lawsuit in response to a March 1 incident in which Barronelle Stutzman refused to provide flowers for Robert Ingersoll and Curt Freed's wedding, despite the two men being longtime patrons of her shop - Arlene's Flowers and Gifts in Richland, which is in Brown's legislative district. Previously, Washington state Attorney General Bob Ferguson filed a consumer protection lawsuit in the case.
Ferguson had sent a letter in March asking her to comply with the law, but said Stutzman's attorneys responded saying she would challenge any state action to enforce the law.
Her attorney, Justin D. Bristol, has said he expects to take the legal battle to federal court and argue Stutzman's refusal of service based on the 1st Amendment's right to free speech.
While Washington voters legalized gay marriage in November, protections against discrimination based on sexual orientation were codified in 2006, in one of the first initial pushes to expand civil rights to the gay community in the state.
Under state law, it's illegal for businesses to refuse to sell goods, merchandise and services to any person because of their sexual orientation.
Josh Friedes, a spokesman for Equal Rights Washington, said that the bill seeks to undermine the state's anti-discrimination laws "and it undermines our entire approach to ensuring the equality of all Washingtonians in commerce."
"It is discrimination, pure and simple," he said.
Brown argued that the bill is not intended to undermine the law or the rights of gays and lesbians in the state and isn't a commentary on same-sex marriage.
"The citizens of the state clearly weighed in on that issue," she said. "It's intended to protect religious freedoms."
Democratic Sen. Ed Murray, a gay lawmaker from Seattle who sponsored the civil rights expansion bill in 2006 as well as the state's gay marriage law, said the proposal seeks to revisit long settled civil rights legislation, arguing that the nation has long moved beyond that discussion.
"I don't think we want to go into our civil rights laws and decide who gets served and who doesn't get served," he said.
Joseph Backholm, executive director of the Family Policy Institute of Washington, said that while he knows the bill is not likely to gain any traction in the Legislature this year, he hopes it sparks a discussion.
"The government is now saying if you have a conviction about an issue that we happen to disagree with, then you as a business owner are going to be fined or shut down because of that," he said. "People should and do have the right to their own convictions."
The measure is Senate Bill 5927.
AP writer Mike Baker contributed to this report.