Death chamber in US
The death chamber is seen through the steel bars from the viewing room at the state penitentiary in Huntsville, TexasREUTERS/Jenevieve Robbins/Texas Dept of Criminal Justice/Handout via Reuters

A new supply of a lethal injection drug has paved the way for the state of Arkansas to go ahead with executing eight death row prisoners in ten days.

Arkansas uses three drugs in the state's lethal injection procedure, but its supply of potassium chloride expired in January 2017. However, Arkansas Department of Correction spokesman Solomon Graves stated on Monday (13 March) that they now have 100 vials of the chemical.

He told ABC: "Coupled with the two remaining drugs, there are enough to carry out the scheduled executions".

Graves declined to say who provided the state with the batch of the drug, due to expire in August 2018, quoting an Arkansas law that keeps the source of the drug anonymous.

He also refused to reveal the cost of the potassium chloride.

Attempts by the death row prisoners' legal team to block the executions were rejected by the state Supreme Court. Judges stated there was no stay in place to prevent the prisoners from being executed.

Lawyers for the men - Don Davis, 54, Bruce Earl Ward, 70, Ledelle Lee, 51, Stacey Johnson, 48, Marcell Williams, 46, Jack Jones, Jr., 52, Jason McGehee, 40 and 35-year-old Kenneth Williams - are seeking to find the state's lethal injection law and the three-drug protocol unconstitutional.

The eight men were convicted of murders committed between 1989 and 1999.

"We're still taking the position that they need to provide this information as to where it came from, who manufactured it, who sold it, etc," Jeff Rosenzweig said. "We haven't yet been successful in that but we're still trying."

Arkansas uses potassium chloride with vecuronium bromide and midazolam. The latter drug renders the inmate unconscious while the other two drugs paralyse the lungs and stop the heart.

Opponents of the death penalty argue that midazolam is ineffective, documenting several executions in other states in which the death row prisoner seems to be in terrible pain before dying.

Republican Governor Asa Hutchinson said: "This action is necessary to fulfil the requirement of the law, but it is also important to bring closure to the victims' families who have lived with the court appeals and uncertainty for a very long time."

The state, which has not put anyone to death for 11 years, has scheduled the lethal injections to take place in pairs from April 17 to 27.

The Arkansas Coalition to Abolish the Death Penalty (ACADP) said: "This planned mass execution is grotesque and unprecedented."