Auckland rates will soar under the Labour-endorsed mayoral candidate Efeso Collins, claims his nearest rival Wayne Brown.

The businessman has pounced on repeated statements from Collins that if he wins the mayoralty rates will be kept within a measure of 5 per cent of household income.

Collins has not told voters how much he will raise rates, only that he will keep rates below the 5 per cent affordability measure set by a major rates inquiry in 2007.

Council financial policy manager Andrew Duncan said Auckland rates currently sit at 3.37 per cent of the median household income. Even if rates rose by 10 per cent, he said, the ratio would only be 3.57 per cent.

To reach the 5 per cent threshold, rates would have to rise by 50 per cent, taking the average household rates bill rise from $3300 to $5000.

Auckland mayoral candidate Wayne Brown says rates will soar if his rival Efeso Collins wins the mayoralty. Photo / Greg Bowker

Brown said for Collins to use the affordability measure as his rating policy is a gobsmacking admission to pay for his big spending promises.

Collins has today repeated his promise to keep rates less than 5 per cent of household income without any mention of how much he will increase rates over each of the next three years if he becomes mayor in October.

Speaking in South Auckland, the Manukau councillor said Aucklanders were facing a cost of living crisis from the ongoing impacts of the Covid-19 pandemic and the unstable geopolitical situation overseas.

He said his policy of free public transport would help and another key way to respond to people's cost of living crisis is to keep rates "within an affordable range, nationally deemed to be on average less than 5 per cent of household income".

Whoever wins the mayoralty will be confronted with huge financial challenges, including an ongoing budget deficit of $90 million to $150m, deferring at least $323m of council and Auckland Transport projects and a looming budget blowout in the $4.4 billion City Rail Link.

Brown said Aucklanders have a stark choice - his promise of getting tough on spending or voting for Collins and "treating ratepayers like an ATM machine".

Brown said he would raise rates by less than the 5.6 per cent increase this year.

Efeso Collins is promising free public transport, but hasn't given any specifics of how to pay for it. Photo / File

The engineer and former Far North district mayor said he could not put a figure on it until he understood the state of the council's finances and the new cost of the City Rail Link.

"I want to reduce rates if I can, but we just don't know enough," he said.

Collins has been leading the mayoral race in the monthly polls since June carried out by the Auckland Ratepayers' Alliance and Curia Market Research. In the last poll of committed voters, Collins was on 22 per cent and Brown was on 19 per cent.

Restaurateur Leo Molloy pulled out of the race when his vote fell from 23 per cent to 15 per cent. Heart of the City chief executive Viv Beck was fourth on 13 per cent.

Voter turnout in 2019 was 35.3 per cent.