The Supreme Court of Alabama has authorized state officials to proceed with what would be the first execution of a prisoner in the US using asphyxiation by nitrogen gas.

In August, Alabama Attorney General Steve Marshall, a Republican, asked the court to allow the state to proceed with gassing Kenneth Smith, who was convicted of murder in 1996, using a face mask connected to a cylinder of nitrogen intended to deprive him of oxygen.

Smith, 58, is one of only two people alive in the US to have survived an execution attempt after Alabama botched his previously scheduled execution by lethal injection in November when multiple attempts to insert an intravenous line into a vein failed.

Smith’s lawyers have said the untested gassing protocol may violate the US Constitution’s ban on “cruel and unusual punishments,” and have argued a second attempt to execute him by any method is unconstitutional.

They also told the court that Smith had not yet exhausted his appeals.

In a brief order issued on Wednesday, the court, whose justices are all Republicans, said Alabama Governor Kay Ivey, a Republican, must set a date for the state’s Department of Corrections to execute Smith.

Two justices dissented from the order and one recused.

A spokesperson for Ivey said her office had not yet determined a date.

A spokesperson for the Department of Corrections said the department is “prepared to carry out the orders of the court.”