The Regulations Review Committee is set to consider a complaint that Wellington City councillors should not have to accept a pay rise following the resignation of one of their colleagues.
Escalating the complaint to this level potentially has implications for local authorities across the country.
The committee acts on Parliament's behalf and examines regulations as well as investigating complaints about them.
Malcolm Sparrow announced last month he was resigning from his role as a Wellington City Council northern ward councillor due to a health scare.
His resignation came less than a year out from the 2022 local body elections, meaning there was no statutory requirement for the council to hold a byelection.
Salaries were increased by more than $8000 per year.
That's because the Remuneration Authority allocates a pool of money to each council. It is the total amount that must be paid in remuneration and is split between councillors.
The authority sets out that each pool must be fully allocated to protect councils from pressure to keep rates down by paying councillors less.
Wellington City councillor Fleur Fitzsimons and Wellington barrister Graeme Edgeler wrote to the authority arguing the policy was unnecessary and inconsistent.
The authority disagreed.
Chairwoman Dame Fran Wilde said the remuneration pool reflected the workload of councils and not individual councillors.
"Malcolm Sparrow's departure has not increased or decreased the workload of Wellington City Council, as the council is doing the same amount of work regardless of the number of members."
Fitzsimons and Edgeler have now complained to the Regulations Review Committee.
Fitzsimons said what they were asking the authority to do was consistent with how it dealt with other temporary vacancies at council.
For example, if a councillor took a temporary leave of absence, their salary could not be reallocated resulting in an underspend.
"The decision from the Remuneration Authority has opened councillors up to criticism not of their own making", Fitzsimons said.
"Although most councillors would donate the difference, everyone would prefer that it wasn't allocated in the first place."
But Wilde said the process minimised pressure of public opinion on councillors as it was clear the authority determined councillors' pay and not the councillors themselves.
Fitzsimons and Edgeler have asked the Regulations Review Committee to request that the Remuneration Authority again reconsider its decision.
"If that doesn't result in a change, we then ask the committee to disallow the Remuneration Authority's decision", Fitzsimons said.
"All Wellington City councillors are united in their view that the remuneration pool should be reduced when a councillor resigns."