A potential partner in the next New Zealand government - the Green Party - says it will advance the case for a national deposit insurance scheme after the September national election.Since abandoning its national deposit guarantee scheme in December 2011, New Zealand has been an outlier in OECD banking markets with zero depositor protection.The previous scheme, introduced at the peak of the Global Financial Crisis in October 2008, was withdrawn three years later mainly because the Reserve Bank of New Zealand was concerned that it had introduced moral hazard into the Kiwi banking system.But that could all change after the September election according to Greens co-leader James Shaw, who wants deposit insurance put back on the policy table."New Zealand is one of the few OECD countries not to introduce a deposit insurance scheme," he said in a phone interview on Monday."Regulators have raised concerns around moral hazard, particularly the prospect that depositors might take their money to riskier institutions knowing that their funds are government guaranteed anyway."However, the market research conducted in New Zealand indicates that depositors are not likely to choose banks on the basis of financial stability but according to whether their parents banked with an institution."Shaw said he wanted to promote competition in New Zealand banking and believes introducing depositor insurance would be a way to loosen the domination of the four big Australian banks."Depositor insurance could help nurture the competitive position of credit minnows such as credit unions," he said."It would increase public confidence in New Zealand-owned banks and potentially deliver them a greater share of the market."Neither of the two major political parties (National and Labour) is likely to win an outright majority in the next parliament and will have to rely on the support of minor parties to form a government. In 2016 the NZ Greens signed a memorandum of understanding with the Labour Party and would be able to begin work on restoring deposit insurance if the two parties returned a majority of MPs at the upcoming election. However, current polling suggests the most likely outcome is National forming a government in coalition with the New Zealand First party. While the RBNZ is likely to offer stern resistance to the idea, leading New Zealand banking experts say it has merit.Professor David Tripe of Massey University believes a 'moderate' deposit insurance scheme could deliver benefits to New Zealand consumers and the banking system as a whole."Retail depositors cannot be expected to monitor the financial position of their bank," he said."The RBNZ has been scaling back the level of public disclosure required to be made by banks, so under those circumstances a moderate depositor insurance scheme within limits would be acceptable."Tripe suggested that any new scheme should insure deposit accounts for up to $NZ100,000 with premiums to be paid by deposit-takers."It should be some sort of risk-based premium," he said."Banks get a benefit from deposit insurance schemes - therefore it should not be free."Australia's four major banks - NAB, CBA, ANZ and Westpac - account