Kentucky has withdrawn its offer of tax breaks for a religious-themed park that would feature a 500-foot-long wooden ark.

Tourism Secretary Bob Stewart said the planned project had evolved from a tourism attraction into an outreach for the Christian ministry that is building it. Stewart wrote in a letter Wednesday to the group’s lawyer that “state tourism tax incentives cannot be used to fund religious indoctrination.”

He said the group was no longer honoring its pledge to not discriminate in hiring for the ark park.

The long-planned Ark Encounter attraction is being built by a nonprofit subsidiary of Answers in Genesis, the Kentucky-based Christian ministry that operates the popular and controversial Creation Museum.

The ark project got preliminary approval in July for up to $18 million in tax rebates.

The group behind the park recently launched a billboard campaign.