Plans to build around 80 to 100 more wind turbines at the London Array offshore wind farm were cancelled today.

That’s after the developers said it would take years before they knew if it would affect a winter habitat of the red-throated loon or diver, an Amber-listed bird (pictured, below).

The world’s largest offshore wind farm was due to expand but its owners DONG Energy, E.ON and Masdar announced they have terminated their lease for the waters with the Crown Estate.

They also cancelled the grid capacity reserved for the project by the National Grid substation at Cleve Hill in Kent.

General Manager Mike O’Hare said Phase 2 of the wind farm has always been “subject to a Grampian condition” that extra turbines wouldn’t affect the Thames Estuary’s status as a designated environmental Special Protection Area.

He said: “We believe it will take until at least January 2017 for that data to be collected and although initial findings from the existing Phase 1 site look positive, there is no guarantee at the end of three years that we will be able to satisfy the authorities that any impact on the birds would be acceptable.”

London Array will continue its research on the effect of new turbines. The owners may decide in 2017 to take another look at the project but there’s no guarantee of this.