New Zealanders are overwhelmingly against pushing sole parents back to work before their children go to school, a Herald-DigiPoll survey has found.

The poll found only 10 per cent support for a proposal by the Government's welfare working group that sole parents should look for part-time work when their youngest children turn 3 - the age at which they become eligible for 20 hours a week of "free" childcare.

The vast majority believe sole parents should have to look for work only when their youngest children turn either 5 (32 per cent), when they can start school, or 6 (54 per cent).

The Government changed the law last year to make sole parents look for part-time work when their youngest child turns 6.

Social Development Minister Paula Bennett said the poll backed last year's law change and ministers were still looking at further changes to be announced this year.

Maori Party co-leader Tariana Turia said parents' circumstances varied "so I believe this is not a question of age but more what is appropriate for each whanau situation".

Act welfare spokeswoman Heather Roy said it was hard to say every sole parent with children above any age should look for work.

"It's really hard to specify a particular age because people's individual circumstances vary hugely."

Labour spokeswoman Annette King said there should be no "arbitrary age" children should be at when sole parents should have to look for work.

Some who could get well-paying jobs and good childcare might return to work after a year, but others with sick or difficult children might need to stay with them into their teens.

Green co-leader Russel Norman said the Greens opposed forcing sole parents to work at any age before their children left school, but supported helping them into work voluntarily.

Auckland University sociologist Louise Humpage, who has tracked public attitudes on welfare issues over the past 20 years, said most New Zealanders thought the unemployed should look for work but were "much more ambivalent" about forcing parents with young children into work.

The welfare working group, chaired by economist Paula Rebstock, recommended that sole parents should have to look for work part-time when their youngest child turns 3 and fulltime when the child turns 6.

It also wanted most people now on sickness benefits to look for work, roughly doubling the proportion of the country's 328,000 beneficiaries who have to look for work from 37 per cent (121,000) now to 77 per cent (253,000).

The report said many countries made sole parents look for work before their children reached school age.

It said Germany, France, Norway and Switzerland already made sole parents look for work when their youngest child turned 3, and most other developed countries treated sole parents the same as any other beneficiaries and made them look for work regardless of their children's ages.

Australia and Britain were alone, with NZ, in deferring the work requirement until the youngest child turned 6. Britain, NZ, Belgium and Australia have the developed world's lowest sole parent employment rates.

Last year 56 per cent of sole parents on the domestic purposes benefit had a youngest child under 6 and 43 per cent had a child under 5.