A new poll by the Maritime Union shows the majority of Aucklanders want the city's port kept in public ownership.

The poll asked 517 Aucklanders whether they thought the Ports of Auckland should be publicly owned.

Of those who responded, 63 percent said yes and 7 percent said no.

The remaining 30 percent were not sure.

The poll's second question included the statement: "Mayor Wayne Brown has suggested selling the Auckland Port to overseas investors".

Brown dismissed that claim and said the poll was irrelevant.

Auckland mayor Wayne Brown. Photo: RNZ / Marika Khabazi

"We're not considering selling the port, so this poll isn't relevant to anything we are looking at," he said in a statement.

However the mayor did confirm that he had considered leasing the port's operations to a private company.

"We are looking at what we can do to get a better return from the operations of the port, which could include a lease," he said.

Maritime Union secretary Russell Mayn said the distinction between a lease and a sale was not important.

"Whether it's leasing or selling, it's still privatisation," he said.

"To the people of Auckland, the difference between a 50-year lease and a sale is nothing.

"If the hang-up is around leasing [versus selling], I'm more than happy to put another poll out. I'm really confident we would get the same result."

Mayn said Auckland Council was working with Australian firm Flagstaff to find an investor.

"We've met with Flagstaff, and they're looking for people to lease or buy the port," he said.

"None of that has been released to the public."

The mayor's office later confirmed that Flagstaff had been involved since before Wayne Brown became mayor.

"Yes, Flagstaff was engaged by council to look at those options before the local election," it said in a revised statement.

Brown said any decision about the port's future would be made with public input.

"If we progress with the idea of an operating lease, that will require full public consultation," he said.

Meanwhile, the Ports of Auckland will deliver its quarterly performance update at an Auckland Council meeting tomorrow. It will be followed by a future strategy update behind closed doors.

The Maritime Union poll, carried out by Talbot Mills last week, followed a report commissioned by the Maritime Union and released in September that detailed how port privatisation in Australia had led to major increases in port charges as private owners sought to recoup their investment.

"This is an asset that is immensely important to Auckland's economy and to New Zealand's supply chain," Mayn said.

He urged the mayor and other councillors to clarify their stances on privatising the port.

Mayn said Brown had a difficult job in dealing with the financial pressures on Auckland City, but privatisation was not the answer.