Indonesia has replied to a written appeal from Foreign Minister Julie Bishop by explaining its strong stance on drug offences.
Chan, 31, and Sukumaran, 33, were sentenced to death for their part in a 2005 scheme to import more than 8kg of heroin from Indonesia into Australia.
Delaney said the Australian Government could do more.
"I think Mr Abbott's initial response was very weak," she told AAP.
When Australian Van Tuong Nguyen was executed for drug offences in Singapore in 2005, Delaney said, there was "absolute outrage" in Australia.
"If this does go ahead I think there will be such visceral outrage and questions will be asked of Tony Abbott - why didn't you do more?," she said.
Abbott said earlier this month that his Government would make "the strongest possible representations" to Indonesia seeking mercy but said it would be foolish to risk jeopardising diplomatic relations.
A spokesperson for Abbott yesterday said the Australian Government would continue to make representations to seek to avoid the execution of Chan and Sukumaran.
Sukumaran is facing execution after Widodo rejected his plea for clemency last month. However, the execution is on hold pending the final decision on Chan's clemency bid.
Indonesian Attorney-General HM Prasetyo said if a crime is committed by more than one person, the executions must be conducted at the same time.
- AAP