The Supreme Court has agreed to hear an appeal against Wellington Airport's proposed runway extension.
The airport wants to extend the runway by 355m to the south to allow long-haul flights to land from Asia.
The case has been bogged down by argument over the length of safety areas at each end of the runway, which must be between 90m and 240m long.
The Court of Appeal recently overturned a Civil Aviation Authority decision to approve a 90m safety area, possibly with an arresting mechanism which is used to rapidly slow a moving plane.
The airport company immediately sought to appeal, saying it must have certainty to run its business.
The Supreme Court has now agreed to the hear the airport's appeal.