''Inequality is one of the most concerning issues facing New Zealanders this election. Both the data and real-world experience of Kiwis proves the poor are getting poorer and the rich are getting richer.''
Grant Thornton partner Peter Sherwin said an OECD survey of income inequality indicated there was no evidence of any sustained rise or fall in income inequality in New Zealand since the research began in the mid-1990s.
The trend line was flat.
The most recent OECD survey ranked New Zealand 19th out of 34 countries on the inequality table. New Zealand ranked equality with Canada, Estonia and Italy. Australia was 24th.
''There is no evidence of growing income equality in the population overall between high-income households and middle and low-income households in the last 20 years,'' he said.
And there was growing evidence of an increasing proportion of dual-earner families, with 66% of two-parent families being dual earners in 2013, up from 50% in the early 1980s, he said.
Mrs Turei said what Mr Sherwin did not point out was in the six years to 1992, when his analysis began, child poverty more than doubled and income inequality in New Zealand grew faster than in any other developed nation.
Over the past 20 years, the rate of child poverty in New Zealand had remained at ''shockingly high levels'', where more than a quarter of all New Zealand children lived below the breadline.
''Successive governments have maintained and tolerated shocking levels of poverty and deprivation among our children.
''The lack of progress for our children is nothing to be proud of - it's a failure.''
Mr Sherwin said there was an issue with child poverty, with 24% of children (200,000) living in households dependent on an adult receiving a benefit and 200,000 children living in a household with no full-time worker.
That was down from 233,000 (22%) in 2010 and 280,000 (30%) in 1998.
Children in one-parent families had a higher rate of income poverty than those in two-parent families.
On average from 2011 to 2013, 16% of European/Pakeha children lived in poor households compared with 28% of Pacific Island and 34% of Maori children. Seventy percent of poor children lived in rental accommodation.
Mr Sherwin said household income poverty was generally considered to be incomes below 40% of the median household income.
Mrs Turei said the wealth of those on the rich list doubled in the past 10 years and much of the new wealth was based on uncounted tax-free capital gains.
It was no longer true only children of beneficiaries were poor. Ministry of Social development data showed the percentage of children in poverty, and whose parents worked was increasing.
''We now have about 40% of all children in poverty living in homes where at least one adult works full-time,'' she said.
