Washington (AFP) - Can a business owner cite her religious convictions in declining to provide service to a same-sex couple?

The conservative-dominated US Supreme Court is to examine the question on Monday in a case that closely resembles one from just a few years ago, pitting religious liberty and free speech rights against anti-discrimination laws.

In June 2018, the nation's highest court partially ruled in favor of a Colorado baker who had refused to make a wedding cake for a gay couple.

The latest case involves a suit filed by Lorie Smith, owner of 303 Creative, a website design company also in Colorado.

Smith has said that as a devout Christian she cannot produce wedding websites for same-sex couples because it would be "inconsistent" with her religious beliefs.

Colorado's anti-discrimination law prohibits businesses from refusing service to someone on the basis of sexual orientation. An appeals court ruled against Smith and she appealed to the Supreme Court.

'To speak or stay silent'

In accepting the case, the court said it would examine whether Colorado's law "to compel an artist to speak or stay silent violates the free speech clause of the First Amendment."

In their brief to the court, lawyers for Smith said she is "willing to create custom websites for anyone, including those who identify as LGBT, provided their message does not conflict with her religious views."

"Forcing artists like painters, photographers, writers, graphic designers and musicians to speak messages that violate their deeply held beliefs fails to comport with the First Amendment's promise of 'individual dignity and choice,'" they added.

Attorneys for Colorado said the law "simply requires that, once a business offers a product or service to the public, the business sells it to all.

"The company can define its service however it wants -- including offering only websites that include biblical quotes describing marriage as the union of one man and one woman," they said.

"But the company must sell whatever it offers to customers regardless of their race, religion, sexual orientation or other protected characteristic," they said.

'Replay of Masterpiece Cakeshop'

David Cole, national legal director of the American Civil Liberties Union, said the latest case is a "replay of Masterpiece Cakeshop," the earlier case involving the baker.

"If the courts were to recognize a First Amendment right of the businesses that sell expressive services to discriminate, then architects could refuse to design homes for Black families," Cole said.

"Bakeries could refuse to make custom birthday cakes for Muslim children. Florists could refuse to provide flowers for a gay person's funeral."

In the previous case, the justices voted 7-2 that the Colorado Civil Rights Commission had displayed anti-religious hostility toward the baker, thus violating his constitutional rights.

The court, however, did not squarely address the issue of whether a business can decline to serve gays and lesbians on religious grounds.

The Supreme Court has undergone a radical transformation since that ruling, with two conservative justices nominated by Donald Trump replacing two liberal justices, giving conservatives a 6-3 majority.

Trump's Republican administration defended the position of the baker in the 2018 case, while this time the administration of President Joe Biden, a Democrat, is backing Colorado and its anti-discrimination laws.

The Supreme Court is expected to deliver its ruling before the end of June.