Unless President Joko Widodo has a change of heart, Chan will likely face the firing squad around midnight on Tuesday (0300 Wednesday AEST), alongside Myuran Sukumaran.
Sukumaran has spent his final hours painting harrowing self-portraits.
Another revealed today, "The second last day" showed him looking skyward, according to his lawyer Todung Mulya Lubis, still hoping for justice.
His brother Chinthu said it wasn't only his family but eight others who were doomed to suffer if Mr Joko can't be merciful.
"I spent the last five hours watching young children playing with their parents," he said.
"I ask the president to not make orphans out of children."
Lawyers for the Australians are keeping up the fight on two fronts.
A constitutional court challenge into the president's clemency obligations has been listed for preliminary hearing on May 12.
And an ex-lawyer from the 2006 trial when they were sentenced to death has finally detailed his claims of interference in the process, alleging judges asked for more than $130,000 for a lenient sentence.
The judicial commission had pledged to investigate but says as an ethics body, it cannot stop the executions.
Mr Lubis says it would be unfair to execute the men if they landed in death row due to corruption.
But the president appeared sceptical.
"Why not convey it at the time, when it actually happened if ... it truly happened, right?" he told reporters in Jakarta.
Attorney-General HM Prasetyo also brushed aside the possibility of the allegations halting the executions.
The men had been given, and had exhausted, all available appeals, he argued.
Mr Prasetyo still won't confirm a time for the executions, but it's understood the families have been told to say their last goodbyes by 2pm on Tuesday.
Adding to their despair, the families lost more than three hours of precious time with their sons and brothers on Monday after being told the visitation rules had changed.
They were later allowed passage to Nusakambangan for what would be their second-last visit.
The notice given on Saturday advised of a minimum 72 hours to their executions but they could be done any time thereafter.
Their friend, Pastor Arif Matius, said when the men were told of their executions both were strong.
He was angry and sad at the punishment.
"We will go down in history as a nation without mercy," Mr Arif told reporters.
"This is how we respond to repented people. This is horrible."
Chan nominated Mr Soper to accompany him for spiritual support before the firing squad, while Sukumaran chose his friend Reverend Christie Buckingham.
Foreign Minister Julie Bishop says she's disappointed Indonesia ignored Australian government requests to delay the execution notices until after Anzac Day.
Despite the representations, Jakarta handed the pair their notices on Australia's "national day of remembrance", Ms Bishop said.
Frenchman Serge Atlaoui has been given a reprieve pending an appeals process, which followed strong diplomatic efforts by France.
Citizens of Brazil, the Philippines, Nigeria, Ghana and Indonesia are set to face the firing squad with the Australians, all denied clemency as part of Mr Joko's war against drugs.
- AAP
