In last week's judgement, the Court of Appeal threw out the High Court's July decision ordering communities secretary Eric Pickles to reconsider an inspector's refusal of an upgrade to Redhill Aerodrome. The Surrey aerodrome had applied to replace a grass runway with a hard runway.
The inspector had ruled that the hard runway would constitute inappropriate development in the green belt. However, Redhill Aerodrome Ltd has since sought to prove that the inspector's approach to green belt policies was too tough.
At the centre of the legal argument is whether the inspector was right to consider "non-green belt factors" such as noise and transport difficulties when weighing up the impacts of green belt development.
In July, Mrs Justice Patterson at the High Court said the inspector should not have taken non-green belt factors into account when making her decision. She said: "The revised policy framework is considerably more directive to decision-makers than previous advice in the planning policy guidance and planning policy statements. There has, in that regard, been a considerable policy shift."
But the Court of Appeal has ruled that the planning inspector's original interpretation was correct. The judgement said that excluding non-green belt harm from "any other harm" would make it less difficult to obtain permission for inappropriate development in the green belt "because the task of establishing 'very special circumstances', while never easy, would be made less difficult".
It continued: "If it had been the government's intention to make such a significant change to green belt policy in the framework one would have expected that there would have been a clear statement to that effect."
Owain Nedin, senior planner at consultancy Nathaniel Lichfield & Partners, said if the Court of Appeal had not overturned the ruling then it may have become easier to secure permission for inappropriate development in the green belt.
He said: "It created potential for an imbalance because decision-makers would have had to consider all the positive planning impacts of a development. But they wouldn't have been able to weigh that against all of the perceived negative impacts, only those related to the green belt."
Duncan Field, partner at law firm Wragge Lawrence Graham & Co, which represents the aerodrome, said: "What we always said was that there is nothing to prevent a decision-maker after they have established what the policy says from looking at any other material considerations, like you do in any normal planning decision."