Cruise ships are one step closer to returning to Lyttelton Harbour as work gets underway on a new berth.

The $56-million cruise ship berth will be located between Cashin Quay and the entrance to the Inner Harbour.

Preparation work began earlier this month and the next phase, pile driving, will begin early next month.

Chief Executive Peter Davie says piling will occur intermittently Monday through to Sunday and the noise levels will be comparable to piling for new buildings in the CBD.

The berth was redesigned earlier this year to help reduce the impact of noise on the Hectors dolphins.

It's due to open by October 2020.