A Texas inmate seeking to stop his execution over claims of religious freedom violations and indifference to his medical needs is scheduled to die Wednesday evening for killing his pregnant ex-girlfriend and her 7-year-old son more than 17 years ago.

Stephen Barbee, 55, is scheduled to receive a lethal injection at the state penitentiary in Huntsville. He was condemned for the February 2005 deaths of Lisa Underwood, 34, and her son Jayden. Both were suffocated at their home in Fort Worth. They were later found buried in a shallow grave in nearby Denton County.

Barbee’s attorneys have asked the U.S. Supreme Court to stay his execution, arguing his religious rights are being violated because the state prison system, in the wake of a ruling by the high court on what spiritual advisers can do while in the execution chamber, did not create a written policy on the issue.

In March, the U.S. Supreme Court said states must accommodate the wishes of death row inmates who want to have their faith leaders pray and touch them during their executions. Texas prison officials didn’t formally update their policy but said they would review inmates’ petitions on a case-by-case basis and would grant most reasonable requests.

Earlier this month, U.S. District Judge Kenneth Hoyt in Houston issued a preliminary injunction, saying the state could only execute Barbee after it had published a clear policy on spiritual advisers that protects an inmate’s religious rights. Last week, the 5th U.S. Circuit Court of Appeals overturned Hoyt’s injunction, saying it was overbroad.