More than 135,000 signatures for Bali Nine mercy petition

A petition pleading mercy for Bali Nine death row inmates Myuran Sukumaran and Andrew Chan continues to gather pace.

More than 135,000 people have signed the petition, actor David Wenham told hundreds of supporters at a candlelight vigil in Sydney on Thursday evening.

Hopes are fading that Sukumaran, 33, and Chan, 31, will avoid an Indonesian firing squad.

Their lawyers in Indonesia are preparing last-ditch legal appeals after the denial of presidential clemency.

"Please don't kill him," Sukumaran's grandmother, Edith Visvanathan, said in an impassioned speech at the vigil.

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

In messages read at the vigil, Sukumaran and Chan thanked their supporters.

"We're amazed how kind and supportive everyone has been. It has helped our families so much."