The amicus brief takes issue with the last-minute stay of execution that Texas Supreme Court ordered Thursday to allow Roberson to appear before a House committee, which voted unanimously Wednesday to subpoena him as part of its investigation into the "junk science" law.

Gov. Greg Abbott is urging the Texas Supreme Court to block Robert Roberson from testifying before a House panel Monday, arguing lawmakers in the committee are effectively usurping state clemency power left solely to him by subpoenaing the death row inmate.

The development comes after several Republican and Democratic state lawmakers issued a subpoena for Roberson to testify at a hearing next week about his case