The co-author of the Houston report on regional processing says Coalition policy could jeopardise regional deal with Indonesia

Towing asylum seeker boats back to Indonesia is not feasible and would risk scuppering a regional processing solution by angering Indonesia, one of the co-authors of last year's Houston report has warned.

Paris Aristotle, part of the three-person panel that ruled out the towing back of boats unless certain conditions were met, told Guardian Australia that there are "enormous risks" to renewed calls to hauling asylum seekers back to where they began their journey.

"The Indonesian government won't be supportive of that policy, the senior expert sources available to us told us that and there were also serious concerns expressed by the defence force," he said.

"They didn't think it would be agreeable or feasible. That isn't me saying that, it's the advice we were given. On top of that, the last thing we want is to make Indonesia even further offside. We need them for a regional asylum seeker system to work.

"I have no idea what will finally be decided, but there is an enormous risk to towing back boats. There's a risk they will be sabotaged as they are being towed back. Nothing has changed, as far as I can see, since our recommendation. If anything, senior ministers in Indonesia have reinforced their opposition to that."

"[The report] is an integrated package. You can't break bits off it and apply them and assume they will work. That will be the case whatever the election outcome."

Opposition leader Tony Abbott has made the towing back of boats an integral part of Coalition policy to slow the arrival of asylum seekers via the sea, claiming that it would send a "clear signal" to people smugglers.

Julie Bishop, the shadow foreign minister, recently told Guardian Australia that high-ranking Indonesian officials had indicated privately that they would co-operate with turning back boats if the Coalition won power.

However, Indonesia's ambassador to Australia, Nadjib Riphat Kesoema, has said the country would not accept asylum seekers from returned boats. Australian army chiefs have also raised doubts over the idea.

Aristotle, director of refugee support organisation Foundation House http://www.foundationhouse.org.au/home/index.htm, said he stood by all of the recommendations made by the panel, which was chaired by former chief of Australia's defence force Angus Houston and also included Professor Michael L'Estrange, but there were "serious shortcomings" in the way the report has been implemented.

"We recommended a far more substantial investment in regional systems and engagement with the highest levels of government," he said. "We recommended $70 million to $140 million for displacement programs and there's been nothing like that kind of money spent.

"We've had parties in the parliament that have point-blank refused to engage with a discussion about Malaysia being part of the regional system. It's clear that some people in parliament won't even negotiate or entertain the prospect of it, despite the fact people are dying at sea."

Aristotle said he was satisfied that improvements have been made to detention on Nauru, where asylum seekers have been housed in tents and have reportedly suffered mental health problems and a lack of legal representation.

However, Aristotle criticised conditions on Manus Island, where the government has begun removing a significant number of children and families. http://www.theguardian.com/world/2013/jun/20/manus-island-children-removed

"Safeguards haven't been met on Manus Island and the progress has been slow," he said. "We recommended safeguards in the report that weren't negotiable. They weren't window dressing."

"Everyone there [on Manus Island] is still in arbitrary detention, the conditions are inadequate, there's no oversight advisory committee monitor safeguards and children are held in detention. Those sorts of things are in no way compliant with what the panel recommended."

Refugee advocates have attacked the Houston report for recommending offshore processing in Nauru and Papua New Guinea, claiming that it amounts to Australia "outsourcing" its human rights obligations and placing asylum seekers in legal limbo with the 'no advantage' rule.

The government's adoption of the report has also come under fire, with a parliamentary committee report released this week finding that Labor's policies had created a system of disadvantage, destitution and arbitrary detention. http://www.theguardian.com/world/2013/jun/19/labor-asylum-boats-policies

Aristotle told Guardian Australia: "There is no perfect solution. But the Houston report is the only humane way to create disincentive to use a people smuggler."

"You've got to process people fairly and properly, you don't want to turn it into a punitive exercise. If you project an image that is harsh and awful, that doesn't make much difference to someone in Afghanistan as it's nowhere near as harsh and awful as being blown up in Quetta.

"The real problem arises when the focus is punitive. You need to treat people equally, that's the only fair way to do it. Then we can start to put a more coherent regional system in place, which is certainly better for asylum seekers than being smashed by waves in the Indian Ocean and being eaten by sharks."