A Government law change will require employers to provide breaks and facilities for mothers to breastfeed.
It will also spell out workers' rights to meal breaks.
Labour Minister Trevor Mallard said yesterday all employers would be required to provide breastfeeding breaks and set aside appropriate facilities, where reasonable and practicable.
This would help mothers' whose children could be brought into work for feeding, or who were in creches nearby. It would also help mothers who needed to express milk.
The law changes will also ban discrimination against breastfeeding mothers.
The Council of Trade Unions and the La Leche League have welcomed the proposed breaks.
La Leche director Barbara Sturmfels said it would help the growing number of mothers who wanted to go back to work after the birth of their babies and keep breastfeeding.
Dr Judith Galtry, a researcher on breastfeeding and the workforce, said the measure was useful but would favour "privileged mothers" and was not a substitute for longer paid parental leave which gave all mothers time to breastfeed.
The last Census showed about 36 per cent of women with babies under the age of one were in paid work - up from 21 per cent in 1986.
"But a lot of people aren't going to have someone to bring in their baby or a creche nearby," Dr Galtry said.
"The people this provision will help will be those who have clout in the workplace and whose employers don't want to lose them. People working in the biscuit factory or as night-shift cleaners are going to find it hard to get that right."
Mr Mallard said the labour market was tight, so it benefited employers to have child-friendly practices to help encourage women back to work.
Some employers might not like it because of the extra cost, but the facilities did not have to be grand.
"We are just talking about making sure there is a comfortable and private place for them to be. No-one is saying it has to be posh."
A National Party spokesman said the measure seemed reasonable provided it did not have unintended consequences.
The new law will also provide for a minimum half-hour unpaid lunch break and two paid 10-minute breaks.
Although most workers already have such breaks through their employment agreements, the law has never included break times.
Minister Maryan Street said about 93 per cent of collective agreements included the breaks, but workers at some workplaces, especially in service and manufacturing businesses, were not getting proper breaks.