Advocacy groups have criticised National's welfare reform policy with one saying Prime Minister John Key is living in a "fantasy world".
Auckland Action Against Poverty said Mr Key's world bore no resemblance to what people on the benefit were going through.
"In the real world the unemployed join queues of thousands of job-seekers to apply for a minimum-wage job at a supermarket and wait all day for an interview that has less chance of success than winning the lotto," said spokeswoman Sarah Thompson.
Child Poverty Action Group co-director Mike O'Brien said the proposal of three distinct benefits did not take into account various circumstances.
"It's very heavily reliant on the availability of jobs. The numbers on benefits have gone up because of issues around the availability of jobs."
Professor O'Brien said despite what most people thought, most sole parents wanted to work but the jobs available often did not fit with the demands of caring for dependent children.
"If the jobs are working night shifts, then that's not going to make a scrap of difference."
Auckland Women's Centre manager Leonie Morris said the idea of a sole mother being forced back into the workforce when her baby was a year old was unfair to her and to the child.
"In terms of part-time work, there's very little available, especially work while the child's at school and [that] has school holidays off.
"The Government's doing nothing to create jobs and that's where their focus should be."