Islamabad: Pakistan’s Supreme Court on Tuesday dismissed an appeal brought by lawyers for a mentally ill prisoner facing execution, and a rights group said he could now be hanged next week.

Imdad Ali, who is aged around 50, was sentenced to death for the murder of a religious cleric in 2002.

He had been scheduled to hang on September 20 in a prison in the city of Vehari despite having been diagnosed with schizophrenia.

Ali received a last-minute stay of execution from the Supreme Court last week. But with that stay now expired, he could receive a new “black warrant” and face execution as early as next Tuesday.

The Justice Project Pakistan (JPP), which is providing Ali with counsel, has sent a mercy petition to President Mamnoon Hussain along with testimony from medical experts.

“It is indisputable that Imdad suffers from serious mental illness,” said Harriet McCulloch, deputy director of the death penalty team at international charity Reprieve.

“There is therefore no doubt that, should Pakistan execute him, it will be committing a grave violation of both Pakistani and international law.

“It is shocking that the system has failed Imdad at every turn — right the way up to the Supreme Court. The Pakistan government must immediately halt Imdad’s execution, and undertake a comprehensive review into how someone who is clearly mentally unfit to be executed has been allowed to come so near to the noose.”

Pakistan reinstated the death penalty and established military courts after suffering its deadliest-ever extremist attack, when gunmen stormed a school in the northwest in 2014 and killed more than 150 people — mostly children.

Hangings were initially reinstated only for those convicted of terrorism, but later extended to all capital offences. The number of those executed since then now stands at 419 from more than 8,000 death row prisoners.

A new report by JPP and Yale Law School issued Tuesday said Pakistan’s criminal legal system is riddled with errors that prevent it from adjudicating capital cases fairly.

It accused authorities of having hanged six people who were juveniles at the time of their offences, in breach of international law, and said the length of time prisoners spent on death row — 11.5 years on average — harms their mental and physical health.