Don't kill Myuran, grandmother pleads during Bali Nine vigil

Myuran Sukumaran's grandmother has delivered an impassioned plea for her grandson's life at a candlelight vigil in Sydney.

"I love him so much," Edith Visvanathan told the hundreds gathered at the Music for Mercy event in Martin Place on Thursday evening.

"I am very, very sad, and very, very weak," she said in an emotional speech after rising from a wheelchair.

"But today I come here to ask a pardon from the president and the people of Indonesia.

"Don't kill him. Please, don't kill him."

Hopes are fading that Sukumaran, 33, and his fellow Bali Nine inmate Andrew Chan, 31, will avoid an Indonesian firing squad.

It emerged on Wednesday the two are among the next group of prisoners scheduled for execution.

"We are all worried and don't know what to do," Mrs Visvanathan said.

"I don't ask for him to come home. I only ask for him to live.

"He has proved himself. He is a good boy.

Earlier, vigil organiser and artist Ben Quilty recalled being struck by Sukumaran's smile when they first met at Bali's Kerobokan prison.

He choked back tears as he spoke of the pain he felt knowing their most recent meeting could be their last.

"Andrew and Myuran did some really bad things," he said.

"But I can tell you, they are good young men now.

Other speakers talked about the men's rehabilitation in Kerobokan prison and the assistance they have given fellow prisoners.

With the initiative of Chan and Sukumaran, the prison now has a computer room, cooking school and guest classes from experts in yoga, dance, reflexology and philosophy.

"Andrew and Myuran are positive, generous young men, humbly pursuing the path to reform," Mercy Campaign co-founder Matthew Goldberg said.

Musicians including Megan Washington, Josh Pyke and Paul Mac performed, each beginning with the phrase of the evening: "I stand for mercy."

In messages sent via lawyers in Bali and read by actor David Wenham, Chan and Sukumaran thanked supporters.

"We're amazed how kind and supportive everyone has been," Sukumaran's message read.

"It has helped our families so much."

"As we face what's coming, we thank everyone who has supported us."

Chan asked the crowd to use the occasion to ponder the meaning of mercy, and to think of those facing execution around the world.

A petition calling for the men's lives to be spared has 135,000 signatures.

The pair's Indonesian lawyer says an application for a second judicial review of their case will be lodged as soon as possible.