Asked by Greens senator Janet Rice if she accepted a minimum income was required to avoid poverty, Senator Ruston replied: "I believe the Australian government provides ... a very comprehensive welfare system to support people who are not in work".

Senator Rice described Senator Ruston's response at an upper house estimates hearing on Thursday as "pretty heartless".

"That's an extraordinary thing to not be able to acknowledge," she said.

"There is a minimum level of income people need to put food on the table, to put shoes on the feet of their children, to pay the rent ... to fulfil their potential, to live healthily."

Ms Ruston was responding during a committee discussion about implementing a national definition of poverty, which the minister said was an "oversimplification" of a complex issue.

"There are a lot of other things that exist within Australia to support Australians, whether that be things like child support ... universal health care system and universal education system," she said.

"There's a whole heap of things that come together to make Australia's welfare system really comprehensive."

Referring to the Australian Council of Social Service's suggestion that a minimum income of $457 per week was needed to avoid poverty, Senator Rice noted JobSeeker payments were just $315 per week.

"That means there are hundreds of thousands of people in Australia, likely millions, who are living in poverty on income support."

Senator Ruston, who argued no government had done more to support people through the pandemic than the Morrison government, said the JobSeeker payments were appropriate.

"It has to be fair to the people who receive it, but it also has to be fair to the people who pay for it," she said.

Australian Associated Press