Westboro Baptist Church, a fundamentalist group which aggressively protests homosexuality, has announced its latest target: Kim Davis.

The Kentucky clerk who was jailed after refusing to issue marriage licenses to same-sex couples will be the subject of a campaign by WBC members.

WBC announced on Twitter that it would picket outside the Rowan County Courthouse where she works on Monday.

The announcement says Davis – who has been married four times to three different men – is among "proud, self-righteous hypocrites that think the same-sex marriage sin is worse than their adultery sin".

"The man that Kim Davis is living with, and calling her husband, IS NOT! Her husband is Dwain Wallace, who she married when she was 18-years-old. It does not matter how many years you pile on! It was adultery at the beginning, adultery in the middle and is indeed adultery today!" the statement continues.

"Note Kim Davis...God will NEVER have same-sex marriage, but he does not require YOU to disobey to deal with this nation."

Also on Twitter, WBC called Davis a "fake Christian", and accused her of breaking "moral compasses".

The Vatican was forced to put distance between itself and Davis after the Pope met with her during his recent trip to the US.

Davis' lawyer claimed that Francis had told her to "stay strong", though Vatican spokesperson Federico Lombardi later said the meeting was brief, and implied that reports of the Pope's support for Davis were exaggerated.