If National are voted into power next year the party will block gangs members from receiving a benefit if they can't prove they don't have illegal income or assets, leader Simon Bridges says.
"As a Crown prosecutor, I saw first-hand the misery gangs peddle," Bridges wrote on social media on Tuesday. "As Prime Minister, I'll make sure gangs can't exploit taxpayers."
More details about the proposed policy would be released on Wednesday in the party's Social Services Discussion Document, he said.
Earlier this month the party announced it was considering such measures.
"It's not beyond the realm of possibility that this is the type of thing we think about," Bridge said at the time.
"We hate gangs. We think they provide misery and a whole lot of bad social impacts."
The party was also understood to be considering fining the parents of early school leavers up to $3000 if their child doesn't enter work, training or further education.
Bridges has taken an increasingly tough line with gangs recently.
Earlier this month he clashed with the head the Mongrel Mob's Waikato chapter Sonny Fatupaito after being invited to an event held by the gang.
Fatupaito offered Bridges an "opportunity to see first-hand the radical changes that are being made in our confederation" with a focus on the wellbeing of the family.
But Bridges declined the invitation, saying although he believed that "there will individual gang members who do good for their whanau and community", he had "seen first-hand the misery caused by gangs, particularly in their crime and peddling of drugs and violence, not least to women".
"Thank you for your letter and invitation, but until you and your gang hand over your guns and stop all involvement in drugs and violence I have no interest in meeting with you."
At that time, Bridges said his party would release a plan to crack down on gangs next year.