No stone will be left unturned for Australian Yang Hengjun as the government supports his navigation through avenues of appeal, but an international law expert says the writer’s life sentence in a Chinese prison is unlikely to be overturned.

Hengjun has received a suspended death sentence for the next two years with a life sentence to follow after being imprisoned on national security more than five years ago.

Foreign Minister Penny Wong confirmed the sentence on Monday, saying the Australian government was appalled by it.

On Tuesday, ahead of parliament’s return, Prime Minister Anthony Albanese also condemned the decision.

“We have conveyed, to China, our dismay, despair, our frustration and to put it simply our outrage at this verdict,” he said.

“This is a very harsh sentence on Dr Yang, who is a man who is not in good health and we’ll continue to make the strongest representations.”

Australia’s ambassador to China will not be recalled, as cabinet minister Tony Burke reaffirmed the government’s commitment.

“We will leave no stone unturned when it comes to any of our own citizens,” he told ABC radio on Tuesday.

The Australian’s saving grace was his dual citizenship, while an execution would open up diplomatic sensitivities, Professor Don Rothwell said.

“Once capital punishment has been imposed, execution follows very soon thereafter,” he said, referencing China’s legal system.

“There’s a bit of wriggle room in terms of this two-year period that allows China to save face by saying, ‘we have this good behaviour period in place’.”

But China was notorious for having exceptionally low successful appeal rates of about 1-2 per cent, Rothwell said.

The case was likely to become a “thorn in the side” of the diplomatic relationship but Australian governments of both persuasions had been loathe to retaliate in other areas like trade, Rothwell said.

“Australia’s greatest capacity to respond is through clear and consistent diplomacy,” he said, adding that partners such as the US and Britain could also add diplomatic pressure.

Chinese ambassador to Australia Xiao Qian was hauled before foreign affairs department secretary Jan Adams for a diplomatic dressing down after the sentence emerged on Monday.

China’s Ministry of Foreign Affairs spokesman Wang Wenbin confirmed Yang had been found guilty of espionage and his property would be confiscated.

“The People’s Court heard the trial in strict accordance with the law, and ensured his procedural rights and of course also respected and ensured the consular rights of the Australian side, and allowed the Australian side to sit in on the sentencing,” he said in a statement.

Yang’s family maintained the writer’s innocence.

“He is in jail because he represents truth, democracy, respectful exchange of rational ideas,” they said through a spokesperson.

Human Rights Watch branded the sentence “catastrophic for Yang Hengjun and his family after years of arbitrary detention, allegations of torture [and] a closed and unfair trial without access to his own choice of lawyers”.

Australians would rightly be appalled and outraged at the sentence, opposition foreign affairs spokesman Simon Birmingham said.

“Moments like these should reinforce to all Australians why our values, rights and liberties are so important to defend and protect,” he said.

Yang was first detained in 2019 on espionage charges but the case against him has never been publicly disclosed.

His trial was held in secret in May 2021.

– AAP