In a letter to a friend, Nguyen Tuong Van says he listens to Chinese music, has an exercise routine and is growing a goatee while in prison.

Nguyen, 25, of Melbourne, is on death row in Singapore after being convicted of drug trafficking and has been sentenced to hang, possibly within weeks.

His lawyers, Australian politicians and Amnesty International have mounted a campaign to commute his death sentence.

In a letter to friend Kelly Ng last week, he describes his desire to protect his mother from his situation and the loss he felt at the death of a friend he had made in prison, who had been executed.

"Today I will spend most of my time with you, as long as it takes, I'm going to make it up to you," he wrote to Ms Ng.

"But I must warn you, Mum's visit and the loss of my dear friend may affect my outgoing letters.

"If you're wondering, I'm OK about all this. Of course, times like this I get to thinking about my own situation.

"I don't want to leave, but I know where I'm going and I know God loves us all."

Ms Ng, who met Nguyen in high school, said he had taken it upon himself to write her a letter every week. He did the same for all their friends, she said.

Nguyen's mother, Kim, described visiting her son in prison, where they would speak through a microphone and he would occasionally put his hand up to hers on the glass.

She began to sob uncontrollably when she described what Nguyen would say to her during her visits. "He always say 'Mum, hold me' and I say 'I hold him forever'.

"I would like to say to the Prime Minister in Australia and the Prime Minister in Singapore please save my family, please forgive my son."

Lawyer Julian McMahon emphasised the relationship between Singapore and Australia, which is its closest ally in the region in terms of education and diplomacy.

Nguyen Tuong Van Case Page & Petition

The West Australian Liberal MP has no sympathy for the plight of Nguyen Tuong Van, 25, who was caught with 396 grams of heroin strapped to his body and in his hand luggage at Singapore's Changi airport in 2002.

He is expected to be executed in the next four to six weeks.

"I haven't got much pity at all for people who deliberately set about importing these drugs," Mr Tuckey told ABC radio in Perth.

"I'm outraged to think that these people consider their life is valuable but not the lives of the people who might take the drugs they illegally bring into our country."

Amnesty International has launched a worldwide appeal to save Nguyen, while the federal government has appealed for clemency.

A petition is now being circulated to all federal MPs, urging signatories to call for a pardon from the Singaporean president and prime minister.

Mr Tuckey said he would not be signing the petition.

"If Australia can use the undoubted friendship it has with the Singaporean political structures to convince them to change their law for an Australian, every drug baron in the world will say next time you want a drug mule you use an Aussie," he said.

"Nobody seems to be considering the lives at risk in Australia from half a kilogram, virtually, of heroin being imported and distributed, presumably through Melbourne.

"I keep reading about kids who die from overdose and nobody signs a petition for them."

Mr Tuckey also said that should Nguyen's sentence be reduced to life in jail, he should not be allowed to transfer to Australia to serve the time on home soil.

"I personally believe they should serve their sentence where they are arrested," Mr Tuckey told the Seven Network.

"We have a bit of a holiday atmosphere in our jails and typically give remissions that are very significant compared to the terms they are given in other countries.

"It's virtually half a kilo of pure heroin - that's probably thousands of hits for young Australians."

Nationals Senate Leader Ron Boswell reaffirmed his strong opposition to the death penalty.

"Human life is the most basic building block of civilised society and should be respected and preserved as a number one priority," Senator Boswell said in a statement.

"This fundamental principle applies in the application of justice, just as it does in other issues and that is why I have today joined many of my parliamentary colleagues in The Nationals and across parties to sign the petition ..."

The federal government is not confident that Singapore will spare Nguyen's life after he lost a clemency appeal last week.

And Singapore's high commissioner to Australia Joseph Koh said Nguyen's plea for clemency had been dealt with fairly and his government could not make an exception.

Mr Tuckey was dumped as regional services minister in 2003 after using his ministerial letterhead to urge South Australia's police minister to reverse a $193 fine against his son Michael.

More recently, he has been on the warpath against Barnaby Joyce, branding the Queensland Nationals senator an "idiot" and a "dopey so-and-so" for his views on the full sale of the government's stake in Telstra.

He questioned why some Australians had been in the disaster zone affected by Hurricane Katrina in the US and was subsequently accused by the opposition of implying the troubles of those people were of their own making.

And when Liberal backbencher Petro Georgiou introduced proposals to water down mandatory immigration detention for children, Mr Tuckey said the move would simply send a green light to illegal immigrants to use their children as pawns.