Mayors will gain new powers, such as appointing their own deputies, under law changes that will come into effect after the council elections.
Local Government New Zealand says the changes will bring councils around the country into line with Auckland's mayor, who was granted the same powers when the super-city was created.
The changes include giving mayors the power to determine the structure of committees, appoint people to committee chairs, and will give them responsibility for setting major plans and budgets.
LGNZ president Lawrence Yule said the changes will make mayors more accountable and stop them from blaming unpopular decisions on councillors.
Mr Yule said they will also let councils get on with important work more quickly.
He said, ideally, mayors will still work with their councils to decide the key roles, but the changes will help where there is division.