Bali nine pair Chan and Sukumaran choose their execution witnesses

• Explosive Bali nine bribe allegations
• The final wishes of the Bali nine duo
• Pair told of execution date

The families of Bali nine pair Myuran Sukumaran and Andrew Chan have received the news they were dreading - they will be forced to say their final farewells on Tuesday afternoon.

The Australians have put in a request for the spiritual advisers who will be alone with them in their final hours before death.

Sukumaran has asked long-time friend and supporter Christie Buckingham, a senior pastor from Melbourne's Bayside Church, who has been visiting both men for years.

Chan has nominated Salvation Army minister and family friend David Soper.

Myuran Sukumaran's mother, Raji Sukumaran arrives at Wijaya Pura in Cilacap, to visit her son.Credit: James Brickwood

They also have the harrowing role of bearing witness at their executions.

Indonesian authorities will need to approve their requests.

The men's Indonesian lawyer, Leonard Arpan, said prosecutors had informed them they must leave Nusakambangan, known as death island, for the last time about 2pm.

The men will be tied to wooden planks in a field and shot about midnight.

Michael Chan's mother Helen Chan leaving Wijaya Pura.Credit: James Brickwood

If the first round of bullets does not kill them, they will be shot in the head by a Brimob commander.

How executions are carried out*:

Nine coffins are delivered to the police station in Cilacap on Sunday.Credit: Aris Andrianto

• Prisoners are executed by firing squad, recruited from a special unit of the national police.
• Recruits for the firing squad are chosen based on their marksmanship and "physical and spiritual health". They are given counselling before and after executions.
• Inmates are moved into isolation cells 72 hours before execution. Families and religious counsellors are allowed visits up to a few hours before execution.
• Prisoners are given the choice to stand, kneel or sit before the firing squad, and to be blindfolded. Their hands and feet are tied.
• Each prisoner has 12 marksmen aiming rifles at his or her heart. Only three of the 12 have live ammunition in their weapons. Authorities say this is so that the executioner remains unidentified.
• Medical personnel are on site to pronounce the prisoner dead after execution.
• Bodies are cleaned and handed over to families, who wait outside the prison during the execution.

Chan and Sukumaran have conveyed simple last wishes.

Sukumaran, whose most recent haunting self-portrait featured a black hole over his heart and two lines of blood, wants to paint for as long as possible.

The coffins in the Cilacap police station on Sunday.Credit: Aris Andrianto

Chan's last wish is to go to church with his family in his final days.

Both Australians also yearn to get out of their isolation cells on Besi prison, which means "iron prison", and walk around in the fresh air.

A man prepares coffins ahead of executions of death row inmates in coming days. Credit: Getty Images

A source, who visited one of the nine condemned men and woman on Sunday, described the humiliation as the prisoners were brought out of their cells still handcuffed.

Tears flowed as they tried to hug family members while their hands were still shackled.

Last days: Andrew Chan and Myuran Sukumaran.

Eventually a guard unlocked the cuffs.

In a further distressing scene, nine coffins were delivered to the police station in Cilacap on Sunday night.

On death row: (from top left) Australians Myuran Sukumaran and Andrew Chan, Frenchman Serge Atlaoui and Brazilian Rodrigo Gularte, (bottom row) Nigerian Raheem Agbaje Salami, Filipina Mary Jane Fiesta Veloso, and Nigerian Silvester Obiekwe Nwolise.Credit: AFP

Cilacap police chief Ulung Sampurna Jaya said 1203 joint personnel would be securing the executions.

The diplomatic fallout has begun with former Indonesian president Susilo Bambang Yudhoyono cancelling a three-day trip to Perth.

Pastors Christie Buckingham and husband Rob Buckingham who have been visiting death row inmates Myuran Sukumaran and Andrew Chan at Kerobokan prison in Bali.Credit: Justin McManus

He was scheduled to speak at the In the Zone Asian leadership forum at the University of Western Australia on Friday.

"It still doesn't have to be this way," a tearful Chinthu, Sukumaran's brother, said.

Chan's brother Michael said Indonesian President Joko Widodo was the only person who could save their lives now.

Earlier this year, the Revered Buckingham told Fairfax Media that the day the Bali nine were arrested in Denpasar in 2005 with 8.3 kilograms of heroin, she wrote in her prayer diary: "How dumb can you get and still breathe? Nevertheless Lord, show your mercy."

Little did she know that a decade later she would be asked to provide spiritual guidance to Sukumaran in his last hours.

For more than three years, Mrs Buckingham and her husband Rob regularly travelled to Bali's Kerobokan prison to visit the men and tirelessly campaigned for their lives to be saved.

"We've never actually seen people so totally reformed," she told Fairfax in January. "They're like us now. They weren't. They are now.

"If you knew them, you would not execute them. I can't even bear the thought."

As unbearable as the thought is, if the Indonesian authorities give their permission, she will be there for Sukumaran for his final moments on earth.

On Monday afternoon, the men's Indonesian lawyer, Professor Todung Mulya Lubis, said they were enjoying spending time with their families, sharing food and stories.

"They are still very optimistic, upbeat and cheerful," he said after a visit on Nusakambangan.

Another of Sukumaran's paintings was brought back from Besi prison on Monday.

Sukumaran told Professor Mulya he was painting his feelings. He said he was also aware of the others in a similar situation to him on death row.

* Source: Nusakambangan prison authorities, Indonesia's National Police, and Attorney General's Office.