Same-sex couples in the US state of North Carolina are to file for marriage licences, knowing they will get turned down, in protest against the state’s equal marriage ban.

The couples planned to file for the licences in the Mecklenburg County Register of Deeds on Wednesday morning.

The couples are supported by the Campaign for Souther Equality, which encourages the practice across the state of North Carolina.

Scott Bishop, who planned to apply for a licence with his partner of 16 years, Ron Sperry, said: “The reason we do it is to shed light on the indignities we face as same-sex couples because the government refuses to recognise our relationships.”

“We’re hoping someone in the south will be courageous enough to step forward and say ‘I believe this to be unconstitutional. I’m going to start issuing licenses,’” said Bishop.

Register of Deeds David Granberry on Tuesday afternoon said he would not grant the marriage licences. He said he supported equal marriage, but that the law prohibited him from issuing them.

In May 2012, voters in the state passed a ban on equal marriage by a large majority, despite failing in Mecklenburg County.

Pennsylvania county clerk D Bruce Hanes previously issued over 170 marriage licences to same-sex couples, and had said he wanted to come down on the “right side of history”, deeming the state’s ban on equal marriage as unconstitutional.

Democrats in the state had said they would appeal against the ruling to block Hanes from issuing further licences, from 12 September.