Auckland Mayor Phil Goff is seeking a second term with a promise of bigger rates increases.

In an exclusive interview with the Herald on Sunday, Goff said general rates would increase by 3.5 per cent a year in his second term — an increase on the 2.5 per cent annual rates rises in his first term.

Goff said he aimed to keep rates low in his first term against all the challenges and pressures on the cash-strapped council, but his long-term budget set rates increases of 3.5 per cent in his second term, which he would stick to.

"I think it's the responsible thing to do to keep rates at a level where some Aucklanders who are under pressure can still afford to pay for their rates but to still deliver the things that our city desperately needs.

"I guess we all want to go to heaven but none of us want to die. We want the services, but we would prefer not to pay any more rates," Goff said.

The mayor came under fire from some quarters over the replacing of a targeted rate for transport with targeted rates for the environment and improving water quality.

Goff said the environment was among his biggest achievements in his first term, saying Aucklanders had got behind the targeted rates to clean up beaches in 10 years, not the 30 years set down, dealing to predators and planting one million trees.

He also introduced a regional fuel tax of 11.5c a litre in July last year and a "bed tax" on hotels, motels and online rentals such as Airbnb and Bookabach.

The mayor said he would keep looking at new ways to raise revenue and said the 10-year budget had efficiency savings targets of $1 billion to spend on things Aucklanders wanted.

Goff is placing trust at the centre of his campaigns as he squares off against former Labour MP John Tamihere, who will have councillor and former National MP Christine Fletcher as his running mate for the October election.

"I will stand on my merits, my integrity, my skill, experience and trustworthiness. Other candidates will have to do the same.

"Every candidate that puts themselves forward for election will need to face scrutiny and prove to the public they are able to be trusted to run the affairs of the city," said Goff, without naming Tamihere, who threatens to take votes off him in south and west Auckland.

This could open the door for a serious contender on the right but so far no-one has come forward to challenge Goff.

John Palino is standing for a third time after finishing fourth in 2016.

Goff said he had a clean bill of health from a heart attack in April last year and was up to the long hours and challenges as mayor of the Super City.

"I have set out a vision of what I want for Auckland.

"I'm pleased with the progress we have made towards that," he said. "It hasn't been easy ... but this is a fantastic city we live in."