A federal judge dismissed a lawsuit Tuesday filed by four death row inmates who claim Mississippi’s method of lethal injection is unconstitutional because it could cause pain.

Attorney General Jim Hood said the ruling clears the way for one of the condemned prisoners, Dale Leo Bishop, to be executed July 23. Bishop was one of four inmates who filed the lawsuit in October 2007. His attorneys filed an urgent motion Monday asking for an injunction because of the upcoming execution.

U.S. District Judge W. Allen Pepper dismissed the lawsuit in a 15-page ruling, saying the inmates were barred by a statute of limitations.

Bishop’s attorneys said they will appeal Tuesday’s ruling to the 5th U.S. Circuit Court of Appeals in New Orleans. They claim the state has withheld information about the way it conducts lethal injections.

“It is important to understand that Judge Pepper did not rule that the Mississippi procedure for lethal injections met constitutional standards,” said Jim Craig, an attorney for the inmates. “The ruling was strictly on procedural grounds.”

The U.S. Supreme Court and Mississippi’s highest court had already denied Bishop’s appeals of his 2000 conviction and death sentence.

“We anticipate a flurry of last minute desperate court filings by the anti-death penalty attorneys,” Hood said. “We believe that the 5th Circuit and the United States Supreme Court will allow this execution to occur on July 23.”

Bishop was sentenced to die for his role in the 1998 claw hammer beating of one of his friends, Marcus James Gentry.

Bishop would be the second prisoner put to death in Mississippi since April, when the U.S. Supreme Court ruled that lethal injection is an acceptable method of execution in the United States. That ruling came after two death row inmates in Kentucky challenged the procedure.

The Mississippi inmates argued that Mississippi’s method is different from the one used in Kentucky. Hood described the procedures as “substantially similar.”

The Mississippi inmates say no monitors are used to ensure that the drugs are taking effect properly. They also claim Mississippi’s execution staff is not properly trained.

The Mississippi Department of Corrections “did not prove that its procedure had safeguards to avoid inadequate anesthesia, which could cause death by suffocation of a conscious, but paralyzed, prisoner,” Craig said.

The argument is that if the first of three drugs used in a lethal injection doesn’t take effect properly, the other two drugs will cause pain but the paralyzed prisoner won’t be able to express discomfort. The first drug administered sedates the prisoner, the second paralyzes and the last kills.

Both Kentucky and Mississippi use the same three drugs for executions.

The inmates in the lawsuit are Alan Dale Walker, Paul Everett Woodward, Gerald James Holland and Bishop — the only one with a scheduled execution date.