The biblical theme park denied more than US$18m (€14.4m, £11.5m) in tourism tax credits because of its discriminatory hiring procedure, has said it will be taking the state of Kentucky, US, to court for what it calls a violation of federal and state law.

Speaking on behalf of Answers in Genesis (AiG) – the group behind Arc Encounter – Mike Johnson, chief counsel for Freedom Guard accused “radical atheist organisations” of applying political pressure to force the state to change its mind.

“You can’t treat religious groups differently than everyone else,” said Johnson speaking to Fox News. “The state of Kentucky like many states, many governments around the US, offers an economic incentive package and they say if you’re going to build a major theme park or a major tourist attraction, we’ll help you by rebating some of the new taxes that you generate.

“Answers in Genesis wanted to do that but when [the state of Kentucky] found out about the religious overtone, suddenly the state changed course. They can’t do that under federal or state law.

Set to open in 2016, Ark Encounter came under fire in October for refusing to hire anyone who doesn’t believe in the biblical flood.

The group behind the attraction – Answers in Genesis (AiG) – asks prospective employees to sign a faith statement, which includes a belief in creationism and the flood. Two days prior to the state’s decision, AiG had threatened to file a federal lawsuit to get the incentives and it looks as though the organisation is about to go through with its threat.

In a statement, Kentucky’s governor, Steve Beshear, said: “It has become apparent that [Answers in Genesis] do intend to use religious beliefs as a litmus test for hiring decisions. For that reason, we cannot proceed with the tourism incentive application.”

AiG however refutes that the hiring process was different from that of any other religious institution in the US.

“It’s well established in federal and state law in Kentucky and elsewhere that a religious entity can employ a religious preference in its hiring,” said Johnson. “There’s nothing unusual or controversial about it at all, that’s how they maintain their identity.

“The state of Kentucky knew these things from the get go and it's disingenuous for them to say that’s a problem now. It’s also unlawful and that’s why they’ve got a problem on their hands.

“They can’t [hire non believers] because it changes their identity, it changes what this theme park is all about. The park is going to go forward but we’re going to have to get this part sorted out probably in the courts.”

In July, the Kentucky Tourism Development Finance Authority voted unanimously to give preliminary approval of the incentives for the US$73m (€54.4m, £43m) first construction phase of the biblical theme park. The 800-acre attraction is set to feature a recreation of a village prior to the biblical floods, as well as a Tower of Babel housing an audio-visual effects theatre and a full-sized ark.