Published: Sep 15, 2011 7:19 PM EDT

TALLAHASSEE, Fla. (AP) - A death row inmate set for execution Sept. 28 again is appealing to the Florida Supreme Court.
    
Lawyers provided by the state for Manuel Valle filed the case Thursday. He was convicted of killing a Coral Gables police officer 33 years ago.
    
The ttorneys are challenging a law that prohibits them from representing death row inmates in non-criminal proceedings. They want to file a federal civil action challenging the state's denial of clemency proceedings in his case but can't because of the law.
    
They say that violates Valle's due process and equal protection rights.
    
The Supreme Court last month lifted a stay of execution after denying Valle's claim a new lethal injection drug would cause pain. A federal appeals court then ordered another stay but also now has lifted it.

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