The wife of an ex-US pilot accused of unlawfully aiding the Chinese military has pleaded for the “deliberate torture” of her husband to end ahead of a final bid to halt his extradition from Australia.

Daniel Duggan has spent 19 months in a maximum-security prison before Friday’s hearing in a Sydney court, where he will fight a US extradition order.

The 55-year-old was arrested in Australia at the behest of the US after being accused of breaching arms-trafficking laws by providing military training to Chinese pilots in South Africa between 2010 and 2012, allegedly receiving about $100,000 for his services.

Duggan’s wife, children and supporters gathered outside Downing Centre Local Court before the extradition hearing to call for his freedom.

“This deliberate torture has to stop today,” Saffrine Duggan said.

Her husband has been kept in a maximum-security prison in solitary confinement, preparing his defence with handwritten notes, while her house has been seized and applications for Legal Aid were rejected, she said.

“They have done everything in their power to make this difficult for my family, to try and break Dan and to break us, but we will fight no matter what,” she said.

Ms Duggan again called on Attorney-General Mark Dreyfus to free her husband.

“He has the power to free Dan … Australians won’t stand for the US threatening our sovereignty, this is Australia, we are Australian citizens,” she said.

Duggan blew kisses and made heart gestures to supporters from the dock as the courtroom filled with supporters on Friday.

The ex-pilot and his family argue the charges are politically motivated given the deterioration of Sino-American relations and how long ago the alleged actions occurred.

In April, he failed in a court bid to postpone the hearing after claiming he had racked up $800,000 in legal bills and was unable to fund his future defence.

In a prison letter seen by AAP, Duggan said he believed his activities were lawful and that the Australian Security Intelligence Organisation and the US Naval Central Intelligence Service knew of his work.

Ms Duggan has presented a petition with 25,000 signatures to politicians in Canberra, calling on Mr Dreyfus to release her husband and end his extradition.

Greens senator David Shoebridge said he would table the petition in parliament.

“Our government should show some guts, our government should make it clear that being an Australian citizen matters, and that when another country comes for you, they’ll protect you as best they can … but we’ve seen none of that,” he said.

“The Albanese Labor government has simply handed this Australian citizen, his family’s assets, their home, handed them over to the United States with barely a whimper.”

This post was originally published on Michael West.