"In 2009 working people were campaigning for a minimum wage of $15. It's taken seven years to get to $15.25. $15 was a fair minimum wage in 2009, it's not a fair wage in 2016."
Labour leader Andrew Little said the "minuscule" rise of just $18 a week in take-home pay "will barely cover rent rises and shows how little the Government cares about growing inequality".
"In the last 12 months the average rent in New Zealand rose by $14 a week, $24 a week in Auckland, showing what a drop in the bucket today's increase is," he said.
This time last year the Ministry of Business, Innovation and Employment advised that a minimum wage increase of up to 3.5 per cent would not affect "overall employment growth".
Mr Woodhouse said in a paper to today's Cabinet meeting that an increase to $15.25 would lift wages for 152,700 low-paid workers but would have "negligible impact on employment growth".
The median wage -- the wage where exactly half the workforce earns more and half earns less -- is currently growing faster than the average wage, meaning that lower-paid workers are closing the gap with those earning around the average wage.
The median wage rose by 4.1 per cent to $22.92 an hour in the last NZ Income Survey for the year to last June, whereas the average wage rose by only 2.5 per cent to $27.49.
A separate survey, the Quarterly Employment Survey, shows that the rate of increase in the average wage slowed to 2.1 per cent for the year to December.