The number of New Zealanders making an exodus to Australia has reached a record high in July, Statistics New Zealand said, which reported that a whopping 53,900 people departed New Zealand to transfer to the resource-rich nation.

Of the total figure, only 14,000 came back the other way, resulting to a total of 39,800 people who have permanently left New Zealand.

It is the highest year-on-year net loss to Australia, according to Statistics New Zealand, which noted that the exodus matched similar losses in the years to the end of April and June, apart from a continuing trend which started last October.

Higher wages and a better standard of living are what prompt Kiwis to take the transfer plunge to Australia.

July's drop, in particular, was driven by the shifting of mid year school holidays to June, said ANZ Bank senior economist Mark Smith, since many people align their moves with the school year. He expects the numbers to increase again next month.

The outflow has likewise impacted New Zealand's population growth. In May, Statistics New Zealand reported the country's number of people grew at its slowest rate in over a decade in the year to March. New Zealand has about 4,430,400 people, although up by 27,700 in numbers, but was however only a dismal 0.6 per cent from a year ago.

"We need to lift the minimum wage, promote industry bargaining, which in Australia covers 60 per cent of the workforce compared with 18 per cent here, and boost productivity while ensuring the benefits flow to workers," Peter Conway, secretary of the Council of Trade Unions, said in news portal www.3news.co.nz.

"Here, we see bosses getting big pay increases here while there is an increasing trend towards casualisation and mistreatment of workers, including low-paid migrants."

RELATED STORIES