The government has accused Labor of wanting to forego billions of dollars for commonwealth coffers with its calls for an end to an automated program to claw back money from Centrelink clients.
Government Services Minister Stuart Robert has defended the "robo-debt" scheme, saying it has resulted in people paying back money owed in 80 per cent of cases over the past three years.
That's added $1.9 billion to the budget bottom line.
"This government, like all governments, has a lawful responsibility to collect where citizens have mismatched what they said they'd earn, versus what through their tax return they have been shown to earn," he told parliament on Tuesday.
"That mutual obligation is something that has been around for decades and decades."
But his figures suggest there are about 160,000 notices sent out which ultimately resulted in the debt being waived or which were incorrect.
The opposition believes there is mounting evidence the robo-debt scheme too often goes awry.
"You now have circumstances whereby they're sending debt notices to the families of dead people. This is not on," Opposition Leader Anthony Albanese told reporters in Canberra.
"I've got an idea for the government: why don't they actually employ some humans to relate to other humans on human services?"
Labor raised the cases of a mother contacted by Centrelink over a perceived debt owed by her son, who had died six months earlier, and a recently widowed pensioner sent a letter about a debt dating back to 1998.
Both cases were uncovered by the ABC in recent days.
Mr Robert apologised for the errors.
"In the vast majority of times, compassion will step in and the debt will be wiped," he said about the first, and noted there had been a mix-up for which his department had apologised profusely in the case of the widower.
But he would not concede to Mr Albanese's question: "When will the government finally admit that its robo-debt experiment has failed?"
Mr Robert said there were more than 373,000 outstanding family tax benefit debts worth $1.3 billion and nearly 409,000 debts owed by Newstart recipients, worth $1.121 billion.
"Does the Leader of the Opposition seriously want be the government the wipe $1.121 billion from 408,000 debts because the member doesn't believe in income compliance?" he said.
Labor's spokesman for government services Bill Shorten said it was time to go back to the drawing board.
"The computerised calculation is claiming false debts that when challenged have led to more than 100,000 claims being changed," he said.
Australian Associated Press