Chan and Sukumaran - their final hours

THE FINAL HOURS:

Indonesian authorities are expected to confirm on Tuesday the pair will be executed as early as midnight.

If so, this is how they are likely to spend their final hours on the Nusakambangan prison island in Central Java.

Times are local and approximate.

* 8.30am (12.30pm AEST Tuesday)

Family members arrive at Cilacap port before travelling to Nusakambangan.

* 9.00am

The families separate to gather together with Chan and Sukumaran.

They included Chan's now wife Feby Herewila, his brother, mother and friends. Chan's father was too ill to make the journey from Australia.

Sukumaran's mother, father, brother and sister and other extended family members were there.

* 3pm

The families leave the prisoners and say their last goodbyes. Chan and Sukumaran return to their isolation cells. The families return to Cilacap.

* 3.30pm

The distressed families speak to the media, pleading with the Indonesian government to spare their loved ones' lives.

"Please don't kill him today, please don't, call off the execution. Please don't, don't kill my son, please don't," Sukumaran's mother Raji wept. Sukumaran's brother Chinthu said killing the men wouldn't stop drug trafficking.

"We did talk about the death penalty, and he knows this is just a waste," he said.

"He knows this is not going to solve anything with drugs, he knows drug trafficking is still going to be there.

"Please don't let my mum and my sister have to bury my brother."

* 11-11.30pm

Team of 12 specially-trained policemen assemble at the execution site.

They take position five to 10 metres from where the condemned inmates will be positioned and lay out their rifles.

The commander loads each rifle with one round.

Only three of the rounds are live.

* 11.30-11.59pm

Chan, Sukumaran and fellow inmates continue to make their final mental and spiritual preparations.

They will be marched from their cells to a clearing.

Their hands and feet will be bound.

They will be placed in front of individual posts and given the option of sitting, kneeling or standing.

Blindfolds will be offered.

The prisoners have a final three minutes with a religious counsellor chosen by the Indonesian authorities.

The commander draws a black mark on the inmate's clothing over the heart.

* 11.59pm-0000am (2.59-3am Wednesday)

The commander raises a sword.

The marksmen take aim and fire when he draws the blade down.

* After midnight

If a doctor determines a prisoner has survived, an officer will fire a single shot to the head with a handgun.

All prisoners are pronounced dead.