Census figures about to be released will show an exodus from the regions, Labour says.
Party leader David Cunliffe says he has his own figures which will be backed up by regional census data due for release tomorrow.
"More than 27,000 people from Waikato have moved to Australia since the last census, 22,600 from the Bay of Plenty and 11,500 from Northland," he said.
"Over the same period 4800 workers have lost their jobs in the Manawatu-Whanganui region, 4700 in Otago and 3400 in Gisborne-Hawke's Bay."
Mr Cunliffe is blaming the government, saying it has ignored the regions and their stagnating economies.
But Economic Development Minister Steven Joyce says Labour is "spinning it" and some of the numbers have been made up.
He says electorate population figures released by Statistics NZ earlier this month don't stack up with Labour's data.
"Certainly there are different regions having different levels of success... but there's very low unemployment in New Plymouth, Canterbury, Southland and Waikato compared with Auckland, which has a higher level of unemployment."
The previous census was in 2006 and Mr Cunliffe has data which he says shows weekly incomes have dropped since then by $45 in Southland, $50 in Waikato and $24 in Taranaki.
Mr Joyce disputes that as well.
"I don't know where they got those figures from, I've seen the income figures and they've actually gone up over that period," he told reporters.