A Green Party spokesperson said:
"Norfolk County Council, controlled by the Conservatives, initiated this judicial review. The review has overturned the previous Labour government's legislation for a unitary council for Norwich. This is a terrible decision for the people of Norwich and for democracy.
"It causes great difficulty for the councillors and the council, but Green councillors in Norwich are ready to step up to the plate. We hope that elections can be held 'as soon as is reasonably practical.' It is outrageous that so many voters have had their electoral choices overturned.
"On the other hand, the Greens are now joint first place on the council. It shows again that Norwich remains the place where the Green Party stands its best chance of taking control of a local authority for the first time."