The Council of Trade Unions says new data from Statistics New Zealand shows Kiwis need to be paid more to make ends meet.
The General Social Survey also showed that Kiwis who rent were less likely to be satisfied with their housing, compared to homeowners.
The data, which comes out every two years, revealed that the number of New Zealanders who said they only just had enough money jumped from 24.4 per cent in the 2017 survey, to 27.1 per cent today.
The Council of Trade Unions (CTU) President Richard Wagstaff said the data showed Kiwis were clearly saying their incomes were too low.
"It is not good enough that almost a third, 33 per cent, of working Kiwis identify that they have 'not enough' or 'only just enough' income to meet their everyday needs," he said.
"This is not financial wellbeing, this is financial struggle."
But Stats NZ data showed the number of people who said they did not have enough money to meet their everyday needs had fallen 1.2 per cent since the last survey.
"This change coincided with a drop in the unemployment rate and several increases in the minimum wage between 2016 and 2018," according to Stats NZ Analyst Claire Bretherton.
Meanwhile, the data showed that one in three Kiwi households rent the homes they live in.
Those people were less likely to be satisfied with their housing compared to people who owned the home they lived in.
"Our latest data showed nine out of 10 New Zealanders were satisfied with their housing, reporting that it was very suitable (44.3 per cent) or suitable (45.0 per cent)," Stats senior analyst Rosemary Goodyear said.
"However, only a third of renters thought their house was very suitable, compared to half of homeowners."
In fact, renters fared worse for all aspects of housing quality measured.
They reported higher rates of cold, mould, dampness and poorly maintained dwellings compared to owner-occupied homes.
Stats also asked people to rate their housing affordability on a scale of 0 (very unaffordable) to 10 (very affordable).
The scale included costs such as rates, insurance and utility bills as well as rent or mortgage payments.
"A tenth of New Zealanders rated their housing as unaffordable (0-3). This was mainly people who rented their home (14.2 per cent), compared to owners (8.0 per cent)," said Dr Goodyear.
Perhaps unsurprisingly Auckland was by far the most unaffordable region, with both renters and owners in Auckland more likely to report their housing costs as unaffordable (with 13.2 per cent rating it as 0-3).