"National keeps making up excuses for the exodus. One day it's mining in Perth. The next it's the sun on the Gold Coast. But the truth is clear. It's the lack of jobs here."
But Economic Development Minister Steven Joyce said Mr Parker was being disingenuous by showing just a few months of data, which he said made a mountain of a small mound.
"The reality is, both unemployment numbers for young people and long-term departures for young people tend to peak in the first quarter of each year once they finish tertiary study at the end of the previous year.
"So he hasn't bothered to show you his graph over a longer period of time, and that would show you, literally, that it occurs every year at that time.''
Mr Joyce said 20- to 24-year-olds were always the most mobile group of New Zealanders and there were plenty of opportunities in Australia in the oil and gas industries - industries which both Labour and the Greens did not get behind here.
He denied claims there were not enough jobs in New Zealand, saying there had been a net increase of 57,000 jobs in the two years to the end of June 2012.
Of those, there were 21,000 more jobs for 20- to 24-year-olds.