State Supreme Court justices want to know whether attorneys for 33 death row inmates who sued over Tennessee's lethal injection protocol would consider any way of executing prisoners to be legal.

Chief Justice Jeff Bivins noted during oral arguments over the case on Thursday that recent U.S. Supreme Court rulings require anyone challenging methods of execution to provide alternative methods under which executions can take place.

Steve Kissinger, one of the lawyers representing the death row inmates, argued that providing alternatives is not a requirement in the lawsuit claiming that Tennessee's one-drug lethal injection method is likely to inflict extreme pain and can cause a lingering death.

Tennessee has not executed an inmate in nearly six years because of lawsuits and problems in obtaining lethal injection drugs.