The US Supreme Court will hear the landmark case on Tuesday (5 December) about a gay couple barred from ordering a wedding cake at a Colorado bakery because of their sexual orientation.

In 2012, baker Jack Phillips of Masterpiece Cakeshop refused to make a cake for David Mullins and Charlie Craig, arguing that it was against his christian belief.

His refusal sparked a legal battle, with Colorado's court finding the baker guilty of unlawful discrimination.

Phillips argues that the verdict violates his rights to religious freedom and free speech.

The US Supreme Court will now determine whether anti-discrimination laws trump religious conviction.

"This case has never been about cakes," Mullins told Fox News. "It's about the rights of gay people to receive equal service in business and not be afraid of being turned away because of who they are. It's about basic access to public life." The couple are being represented by the American Civil Liberties Union (ACLU).

Their lawyer Louise Melling told Reuters: "This is not a case about a cake. It is a case about a very radical proposition." She said that Phillips' defence team was "asking for a constitutional right to discriminate".

"I serve everybody that comes in: gay, straight, Catholic, Muslim, atheist. I welcome everybody into my shop," Phillips recently told Fox News. "I just don't create cakes for every event that's presented to me."

Phillips argues that the First Amendment protects his freedom of expression and his decision to decline to make cakes with messages contrary to his personal beliefs. Phillips, who says he has lost customers as a result of the controversy, is represented by the conservative Christian legal group Alliance Defending Freedom.

"It's not about turning away these customers, it's about doing a cake for an event - a religious sacred event - that conflicts with my conscience," he said. "My bakery, my family, my life, the work I get to do, is a gift from God and I want to honour Him in everything I do."

Baker Jack Phillips
David Mullins Charlie Craig gay wedding cake
Baker Jack Phillips refused to make a wedding cake for gay couple David Mullins (L) and Charlie Craig