Detained Australian writer Yang Hengjun says he will "face suffering and torture with resilience" in a letter to his family released ahead of his trial in China.
In a letter understood to have been dictated from detention in March, Dr Yang tells his supporters - including his sons in Australia - "don't worry about me" and urges them to preserve his writings.
Dr Yang will be tried on charges of espionage in a closed Chinese court on Thursday after being held in Beijing for more than two years.
Since his detention, the 55-year-old blogger has had no access to his family and limited access to his lawyer.
The letter, seen by SBS News, was released on Wednesday ahead of his trial getting underway.
In the letter, Dr Yang says he has been held "in confinement for 26 months now without fresh air or sunshine".
"This has made my health deteriorate," he says.
Although he says he is "spiritually strong" and will "face each day with dignity", he urged his followers that "if the worst comes to the worst, if someone wants to take revenge on me for my writings, please explain to the people inside China what I did, and the significance of my writing to people in China".
"There is nothing more liberating than having one’s worst fears realised. I have no fear now. I will never compromise," the message reads.
"The values and beliefs which we shared, and which I shared with my readers, are something bigger than myself.
"If I get out, I will write articles to improve Australia-China relations and that will help China to understand the world, and the world to understand China."
Prominent Chinese-Australian writer Yang Hengjun has been detained in China since January 2019. Source: Facebook
Foreign Minister Marise Payne is calling for Dr Yang to be given a fair trial.
"I very much hope Dr Yang is provided with a fair trial but we have not seen any explanation or evidence of the charges brought against him," she told ABC radio on Thursday morning.
"We are not interfering in China’s legal system, the concerns we’ve raised are legitimate ones."
She said Australian diplomats have sought to observe Dr Yang's hearing and raised concerns over his "delayed and limited" access to legal representation, and she expects "basic international standards of justice to be met".
Labor senator Penny Wong said on Saturday the opposition was deeply concerned that Chinese authorities had failed to provide any explanation or evidence for the charges.
"We strongly support the government's advocacy for Dr Yang, including through consular assistance, and are disappointed that he has not received basic standards of justice or procedural fairness consistent with China's international legal obligations," she said in a statement.
Senator Wong said China also had obligations under the Australia-China bilateral consular agreement. As a result, Australian officials should be permitted access to Dr Yang's hearing and he should be granted advanced access to his lawyer and consular officials in advance.
The Law Council of Australia on Wednesday joined calls for Chinese authorities to permit Dr Yang access to legal and consular assistance.
“The right to independent legal assistance must be ensured from the moment of deprivation of liberty, and access to effective legal representation guaranteed to all persons at all stages of criminal proceedings," Law Council President Dr Jacoba Brasch QC said.
“This is a fundamental precondition to realising the right to a fair trial.”
Dr Yang's trial had been due to start in January but has been delayed by four months.
He faces a lengthy jail sentence if found guilty on charges of endangering national security by joining or accepting a mission from an unidentified espionage organisation.
Dr Yang was detained by Chinese authorities in January 2019 at Guangzhou Airport after arriving from New York.
Australia has consistently lobbied in his support and that of a second detained Australian, journalist Cheng Lei, who has also been held on suspicion of endangering national security.
With Reuters, Tom Stayner.