Bill Farmer, former ambassador to Indonesia, told a high-level forum in Canberra that Australia's Prime Minister either didn't understand the damage he was doing, or didn't care.

"Prime Minister Abbott seems to have a tin ear for international dealings or at the very least a tendency to let domestic politics trump international policy," said Mr Farmer, addressing the Crawford Australian Leadership Forum at the Australian National University on Monday.

He said Mr Abbott's turn-back policy could have been implemented smoothly, without damaging relations, if it had been done respectfully and with clear communication, as had been the case under previous Australian governments.

Indonesian foreign minister Marty Natalegawa however, told the same forum that the turn-back policy was an insurmountable bilateral problem. The unilateral nature of the policy was "inherently incompatible with good bilateral relations between our two countries".

This inevitable damage needed to be mitigated by clear and timely communication, he said.

"It is not absolutely impossible to have some kind of accommodation in the implementation of such a policy, but not after the event," said Mr Natalegawa.

Mr Natalegawa was foreign minister for five years under President Susilo Bambang Yudhoyono, in what was widely seen to be a foreign policy-focused and Australia-friendly regime. 

He said he and Foreign Minister Julie Bishop had steered through earlier difficulties by exchanging text messages almost every day.

Mr Farmer's views carry extra weight because he was secretary of the Department of Immigration for seven years, spanning Mr Howard's controversial "children overboard" election campaign. Mr Howard appointed him as ambassador to Jakarta in 2005.

Mr Farmer took aim at three-word slogans, such as "stop the boats" and "nope, nope, nope".

He urged Australia to "throw away the megaphone" and treat Indonesia's young and voluble democracy with "respect".

"We go too readily for the dog whistle," said Mr Farmer.

Mr Natalegawa criticised the new Indonesian president, Joko Widodo, for adopting a narrow, mercantilist and domestically-focused foreign policy.

He said narrow objectives were being met at the the expense of democratic values and broader regional objectives, as exemplified by the noisy anti-drugs campaign that led to the executions of Andrew Chan and Myuran Sukumaran.

But Debnath Guharoy, Asia director of Roy Morgan research, noted that Jokowi was not as weak and purposeless as often portrayed, noting that opposition leaders were working with him inside parliament and that his domestic approval rating was 70 per cent.