Len Brown has issued a please explain to Ports of Auckland over the dismantling of Marsden Wharf.

The port is starting to dismantle the northern edge of the wharf after receiving regulatory approval three years ago.

But councillors are debating the wharf's future and the mayor says they were never told about the work.

"You and I as ratepayers of Auckland, we own that port 100 percent.

"But at the same time, it sits in one of the most beautiful harbours in the world.

"This is all about good strong collaboration work and relationship between the representatives of the ownership of the port and the port itself."

The port's future expansion should be restricted by a proposed new waterfront layout and Unitary Plan rules.