Labor MPs have continued to distance themselves from comments by Families Minister Jenny Macklin, who caused a furore by claiming she could survive on the dole.

Ms Macklin angered welfare groups by claiming she could live on Newstart payments of $246 a week - or about $35 a day - while defending cuts to single parents' benefits.

The minister, who earns about $850 a day, has since been challenged to prove it, while her Labor colleagues have dodged answering whether they too could survive on the dole.

Treasurer Wayne Swan admitted it would be tough to survive on $35 a day, which was why the government offered low-income families a range of "generous" extra payments.

Newstart was indexed annually against inflation and was boosted by additional benefits such as the School Kids Bonus and Family Tax Benefits A and B, he added.

"For people on low incomes they're very generous payments," Mr Swan told reporters on the Sunshine Coast on Thursday.

"We make them because we're a Labor government that absolutely understands it's tough to get by on low incomes."

He refused to say whether he could live on the dole, or whether the Gillard government would continue increasing the Newstart allowance.

The Australian Council of Social Service claims Newstart hasn't been increased in real terms for nearly 20 years and must be raised by $50 per week to prevent worsening poverty in Australia.

Ms Macklin's comments also drew the ire of the 84,000 single parents eligible for parenting payments, who since January 1 are being moved to the Newstart allowance when their youngest child turns eight.

The Australian Manufacturing Workers Union joined a growing chorus on Thursday calling for Newstart to be increased, arguing it keeps the jobless in poverty and makes it difficult for them to find work.

"On 35 bucks a day you can barely feed and clothe yourself, let alone pay rent or a mortgage, catch public transport or drive a car to a job interview," national secretary Paul Bastian said in a statement.

Health Minister Tanya Plibersek also wouldn't say if she could get by on $35 a day, but conceded it would be very hard to live on an income support payment.

"I don't think anyone thinks it's easy to live on Newstart," Ms Plibersek told ABC radio on Thursday.

The government understood the challenges of surviving on income support, which was why Labor had put extra money into age and disability pensions and carers allowances, she added.

Acting Greens leader Adam Bandt has challenged Ms Macklin to join him in living off the dole for a week, prompting Housing Minister Brendan O'Connor to accuse the MP of patronising those on the payments.