Their constitutional role, as laid out in the Local Government Act 2002, is to provide leadership to their councillors and citizens of their districts, and to guide the direction of council plans and policies.
Attempts to set up local government following the signing of the Treaty of Waitangi in 1840 were complicated by the small and spread out population of European settlers in New Zealand.
The New Zealand Constitution Act 1846 enabled municipal bodies to be created, though this legislation was suspended from 1848 for five years.
Provincial legislative councils were set up based on the proposed provinces in the 1846 Act, though with both elected and unelected appointments they were seen as unsatisfactory towards the goal of self-rule.
It was thought that these would suffice for local representation but municipal governments were created anyway in Auckland, Dunedin, and Christchurch.
[6] The powers of these authorities was legislated in 1867 with the Municipal Corporations Act, establishing responsibility over gasworks, libraries, and other public utilities.
[3] Suffrage for these bodies was limited to individual male property owners, which disenfranchised Māori as collective ownership was more common amongst them.
[15] When the councils surrounding Auckland were merged in 2010, a more defined set of powers for mayors in all parts of the country was implemented into the existing Local Government Act 2002.
[18] Mayors in New Zealand are considered weak in terms of the level of executive power they can wield, as granted to them via legislation.
Councils are empowered to endeavour to achieve the "four well-beings", specifically the social, environmental, cultural, and economic health of their communities.
[20] Mayors report that they utilise de facto powers to achieve their goals as leaders, including their ability to build relationships with their communities, other councillors, mana whenua, and central government.
[21] Mayors who worked closely with their councillors, those that built personal relationships and trust, were more successful at seeing their policies and goals to fruition than those that took a more hard line, less co-operative approach.
[22] Unlike local bodies in other countries, the central government provides a minute fraction of a council's income, with upwards of 80% coming from rates.
[19] Councillors and mayors in New Zealand are not usually affiliated with political parties,[23] leading to challenges with reaching consensus amongst people elected on individual-mandates.
The intrusion of party politics into local government is commonly seen as distasteful, though there has been a rise of affiliated candidates in Auckland and Christchurch since 2007.
[24] A balance must be navigated between the mandate given to the mayor from the public and the political reality of working with a team of disparate people.
[21] Explicit corruption at the local level has not been seen to be a major issue, though the absence of a party structure has been seen as something that could lead to a greater risk of clientelism, with members potentially showing favour to supporters and disfavour to opponents.
Central government has appointed commissioners and other oversight mechanisms in the past when, in their view, a council was not functioning.
[22] The principal legislation outlining the formal and constitutional powers and responsibilities of the mayor is the Local Government Act 2002, specifically section 41A.
[21] The mayor is to provide leadership to the councillors and people of the district,[26] and to lead the development of the council's plans and policies.
[33] Two electoral systems are used at the local level within New Zealand, first-past-the-post (FPP) and single transferable vote (STV).
These include being a citizen of New Zealand, securing the nominations of two people on the electoral roll within the area, and paying a deposit of $200.
The Human Rights Commission has called the under-representation of Māori in local government "one of the top ten race relations challenges" in the country.