Local Government Act 1993 No 30
Current version for 1 July 2020 to date (accessed 4 August 2020 at 19:21)
231   Deputy mayor
(1)  The councillors may elect a person from among their number to be the deputy mayor.
(2)  The person may be elected for the mayoral term or a shorter term.
(3)  The deputy mayor may exercise any function of the mayor at the request of the mayor or if the mayor is prevented by illness, absence or otherwise from exercising the function or if there is a casual vacancy in the office of mayor.
(4)  The councillors may elect a person from among their number to act as deputy mayor if the deputy mayor is prevented by illness, absence or otherwise from exercising a function under this section, or if no deputy mayor has been elected.