A calligraphy studio in Arizona is suing the city of Phoenix, in what is the latest legal challenge to LGBT non-discrimination taking place across the US.

Joanna Duka and Breanna Koski, owners of Brush and Nib, filed a lawsuit with the state court last Thursday, arguing that the city’s anti LGBT discrimination law infringed on their right to free speech.

They have claimed that as Christians, they are being forced to service same-sex couples and this contradicts state-wide protections on religious freedom and free speech.

The city’s ordinance bans businesses from refusing services based on sexual orientation and can lead to fines of up to $2,500 or six months in jail for everyday they don’t comply.

Jon Scruggs, an attorney working on the case with Christian group, Alliance Defending Freedom (ADF), said: “We fully expect to have a hearing in the next few weeks on our motion for preliminary injunction and to have the Arizona superior court grant our motion and vindicate the free speech and religious liberty rights of our clients.

“In reality, the case is pretty simple when you boil it down: no American, including artists, should have the government force them to create art against their artistic and religious beliefs.”

The main argument being put forward by the studio is that calligraphy is art and as such it cannot be censored or controlled by the Government.

The lawsuit also aims to win over judges by giving a detailed description of Ms Duka and Ms Koski’s religious journeys and how they went about setting up the business.

A number of cases are currently take place across the country, including one where a barber refused to cut a trans man’s hair and another which allowed a student to wear a ‘Nobody know I’m a lesbian’ shirt to school.