Kiwibank would get a $100 million capital injection to turbo-charge its expansion and create more competition in the banking sector, under Green Party policy.
In announcing the policy today, co-leader James Shaw said a lack of competition among the big Australian-owned banks meant Kiwis were missing out on lower mortgage rates.
"Beefing up" Kiwibank would lead to lower interest rates and could save homeowners hundreds of dollars, Mr Shaw said.
"Under our plan, a first-home buyer in Auckland with a $500,000 mortgage could save $690 a year, meaning they pay off their mortgage earlier."
Across the entire economy, these mortgage savings alone translate into savings of $312 million a year.