Ports of Auckland is returning serve over claims it could have demolished the Marsden Wharf instead of making controversial extensions to another area.

Urban Auckland says the ports could have done that instead of extending Bledisloe Wharf by 92 metres.

But the port company says that's not true - and Urban Auckland would know that, if it had come and talked to it.

Ports of Auckland head of communications Matt Ball says while Marsden Wharf will be removed at some point, the Bledisloe Wharf still needs to be extended.

"What they've said is misleading. They either don't know the facts or they do know the facts and they're not telling people.

"Removing Marsden is actually quite difficult. It's in our long term plan, but it's not a short term answer to the problem in front of us."