The United Church of Christ (UCC) announced it is suing the US state of North Carolina over its gay marriage ban.
The liberal Christian denomination announced the legal challenge today, 28 April.
The church claims the state's prohibition, known as Amendment One, infringes on the free speech rights of clergy.
'The United Church of Christ is proud to defend the religious freedoms upon which this nation was founded,' the Rev. Geoffrey A. Black, general minister and president of the UCC, said in a statement.
'It is unfortunate that, even today, laws are designed to treat gay and lesbian people unequally,' Black continued. 'In its efforts to restrict gay marriage, the State of North Carolina has restricted one of the essential freedoms of our ministers and of all Americans.'
According to the activist group Freedom to Marry in 2012 voters in the US southern state passed Amendment One. The statute bans marriage equality and 'prohibits same-sex couples from attaining any form of legal family status.'
The UCC suit adds the law makes it a crime for religious officials to officiate a wedding between two people who lack a valid marriage license.
'United Church of Christ ministers, interested in conducting a religious marriage ceremony for same-gender couples, could face up to 120 days of jail and/or probation and community service if found guilty, since North Carolina marriage laws define and regulate marriage as being between only a man and a woman,' the church's statement said.
Joining the legal action is the Rev. Nancy Allison, senior pastor at Holy Covenant UCC in Charlotte, North Carolina.
'When gay and lesbian congregants come to me asking that I perform their wedding, I want to be able to offer them both the blessing of Holy Covenant United Church of Christ and that of the state of North Carolina,' the UCC minister said in a statement.
'It is time to challenge an unjust law and bring greater freedom to every religious leader in North Carolina,' she continued.
In 2005, UCC became the first mainline Christian denomination to support gay marriage.
Black recorded the below video presentation about the lawsuit.