Former Indonesian constitutional court chief justice Jimly Asshiddiqie, who was a key player in the anti-death penalty lobby in Jakarta in the lead-up to the executions on April 29, said the push for Chan and Sukumaran to die had come from Indonesian President Joko Widodo personally.

In an unprecedented insight into the inner workings of the Indonesian government, Professor Jimly also confirmed to Fairfax Media that Indonesian Vice-President Jusuf Kalla had been part of a small group pushing back, ultimately unsuccessfully, against the executions.

But he said several issues, including the Corby family's reaction to her clemency, granted in 2012, and her release on parole in 2014, were among the key negatives in the campaign.

"[Former president] SBY [Susilo Bambang Yudhoyono] once gave clemency to Corby, and ... she still spoke very badly about Indonesia. She never showed her thanks, or expressed any thanks to Indonesia," Professor Jimly said. "This created a very bad impression among the Indonesian public."

After Ms Corby was release on parole in February 2014, her sister, Mercedes, did an exclusive interview on the Seven Network in which she speculated that the drugs found in the infamous boogie board bag "could have been from Indonesia" - suggesting Schapelle was set up.

This gave fuel to an already massive media campaign against Corby's release on parole.

Another factor weighing against clemency for Chan and Sukumaran was a poll conducted by Roy Morgan Research for youth radio station Triple J.

Professor Asshiddiqie, one of Indonesia's most senior jurists and respected human rights lawyers, said this poll was seized upon by Mr Joko to conclude that "the majority of the people in Australia don't care about the executions - only the minority gets angry with Indonesia".

"So they think this is only about Abbott's politics, not Australia as a whole ... the [Indonesian] government thinks this is not hurting the people of Australia, it's only elites, who claim to be popular by misusing public anger," Mr Jimly said.

That conclusion had "made the Indonesian government become more strong in their position".

The poll - based on an SMS sent to Roy Morgan's database of users for the Triple J Hack program - asked: "In your opinion if an Australian is convicted of drug trafficking in another country & sentenced to death, should the penalty be carried out?"

Of 2123 respondents, 52 per cent tapped "Y" on their phones in response.

Professor Asshiddiqie - whose advocacy on behalf of the condemned men prompted one Indonesian government minister to suggest he was an Australian spy - also agreed that Mr Abbott's comment reminding Indonesia of Australia's $1 billion in tsunami aid was a blunder.

It prompted a sarcastic social media-led campaign in Indonesia to collect "Coins for Abbott" to return the aid money.

Mr Abbott's comment was "very bad. Better Julie [Bishop]," Professor Asshiddiqie said. "Julie was more diplomatic".

Professor Asshiddiqie has said lobbying had helped bring about two pauses in the rush to execution - the first in March, the second in April - but could not stop it entirely because Mr Joko was determined.

He also said that despite Australia's blunders, by the beginning of 2015 it was unlikely that Mr Abbott's government or civil society could have done anything to change the president's mind.

Mr Joko was under pressure from the anti-narcotics agency and from a popular push against drug traffickers in general, and pressure from other countries only increased his determination.

"He would like to show that he is independent," Professor Asshiddiqie said. "The more he is negatively responded by other countries, the more he stuck to his point. He is Javanese."

Professor Asshiddiqie has suggested a number of ways in which Indonesian law could move away from the death penalty, including the use of provisions in Islamic tradition.