New Zealand First is calling for a review of the Recognised Seasonal Employers (RSE) scheme, to stop it being used as a back door for gaining residency in New Zealand.
The RSE scheme allows people from Pacific island nations to come to New Zealand on temporary visas to work in orchards, vineyards and market gardens.
It has been hailed as a success in helping to plug labour shortages during the harvests and providing Pacific communities with income and training.
However, New Zealand First Leader Winston Peters said the scheme needed to be looked at because a growing number of visa holders in the programme were obtaining residency on the basis of partnerships formed while they were working here.
He described it as the immigration equivalent of speed-dating and said it was not how the scheme was envisaged to operate when it was set up while he was foreign minister in 2008.
'It was never intended to be a back door towards immigration into New Zealand and that's what it's rapidly become. We've gone from 2008 to having no-one applying in that way, to figures like 40 and 38 a year now and it's starting to build," Mr Peters said.
"Frankly, that's a perversion of the policy - not in any way what the overseas governments, who organised it with New Zealand, wanted.
"They wanted there to be a category of seasonal workers coming from their countries, to help build their own economic value with remittances back home. When the people went back home they'd saved a significant amount of money.
"It enabled also others to come from those countries like Samoa and Tonga, the next year. But when things like this change, then some people in those countries miss out and someone has come through the back door by way of immigration."