The US Supreme Court will judge on whether a Christian baker discriminated against a gay couple by refusing to make their wedding cake on religious grounds.
The landmark case was taken up on Monday - two years to the day after America's top court legalised same-sex marriage nationwide.
Charlie Craig and David Mullins filed a complaint under Colorado's anti-discrimination laws after Jack Phillips, owner of Masterpiece cakeshop, told them in 2012 he wouldn't make them a wedding cake due to his religious objections to gay marriage.
Lower courts have ruled against Phillips saying his right to exercise religious freedom did not outweigh the gay couple's protection under anti-discrimination laws.
Phillips has argued that being required to make wedding cakes for gay couples violated his right to free speech and his freedom of religion.
Colorado's appeals court rejected that argument, saying complying with the law is not the same as compelling someone to 'endorse' something they don't agree with.
'Masterpiece remains free to continue espousing its religious beliefs, including its opposition to same-sex marriage,' the court ruled.
But as a public business it is banned 'from picking and choosing customers based on their sexual orientation', it added.
Despite lower courts' consistent rejections of Phillips' case and others like it, the new makeup of the Supreme Court – with Neil Gorsuch's appointment restoring the balance towards the conservatives – may mean the top court will back the religious liberty argument.
A recent poll found most religious Americans oppose allowing businesses to refuse gay couples services based on their religious beliefs,
Around 61 per cent of Americans think businesses should not be allowed to refuse gay people goods or services, even if doing so violates their religious beliefs, the survey from PRRI found.
Unitarians were the most strongly opposed with 87 per cent saying they disagreed with the plan but even more socially conservative groups such as black Protestants (66 per cent), white Catholics (61 per cent) and Muslims (60 per cent) did not agree.
White evangelical Protestants stand alone as the only religious group where a majority do not oppose the move but even there the support was split with 50 per cent saying they were in favour and 42 per cent opposed.
