NASHVILLE (AP) — Attorneys are asking the U.S. Supreme Court for a stay of execution for a convicted child killer after the Tennessee Supreme Court and governor decided against a delay.

In a filing Tuesday, federal public defender Kelley Henry and attorney Carl Gene Shiles Jr. wrote that there should be a stay of Billy Ray Irick's scheduled lethal injection Thursday while a challenge of the state's protocol continues on appeal.

The state Supreme Court wrote Monday that Irick's attorney didn't meet the burden of proving that the lawsuit challenging Tennessee's new three-drug cocktail is likely to succeed. Also Monday, Gov. Bill Haslam said he won't intervene.

Irick would be the first inmate Tennessee has executed since 2009. He was convicted of the 1985 rape and murder of a 7-year-old Knoxville girl.