The Labour Party says the Reserve Bank's focus should be widened to cover the stability of the dollar and other factors, as well the containment of inflation.
It has drafted a bill requiring the bank to aim for a stable currency, full employment and the prosperity of the people of New Zealand.
Labour leader Phil Goff says targeting inflation would remain a crucial goal but should not be the sole focus.
He says such a move would bring New Zealand into line with Australia and most other developed economies.
Mr Goff told the Federated Farmers annual conference in Invercargill on Thursday that New Zealand is unusual internationally in having a single policy goal for its Reserve Bank.
Labour also wants to give the bank more tools to supervise and regulate banks' overall lending, with respect to wider economic risks, and pledges to maintain the bank's independence from government.