Despite the latest legal victory, Heathrow expansion still has a lot of obstacles to navigate

At the conclusion of any court case, the terms that naturally present themselves are “victory” and “defeat”. It is tempting to regard the High Court’s dismissal of all five legal challenges over expansion at Heathrow as a 5-0 trouncing by proponents of the third runway.

Surely, the ruling by Lord Justice Hickinbottom quashes the environmental arguments against airport expansion, as well as the commercial case brought by Heathrow Hub for an extended northern runway, once and for all?

But as someone who has followed the interminable saga of airport expansion in southeast England for decades, I suggest you don’t pop 2026 in your calendar just yet as the date when a new runway will open.

The High Court encounter was little more than an opening skirmish. Neil Spurrier of Twickenham, five local authorities, the Mayor of London, Greenpeace, Plan B and Friends of the Earth challenged the transport secretary, Chris Grayling, on key environmental aspects: air quality, noise and the climate change effects of expansion.

But as the judgment makes clear: “The court was solely concerned with whether the secretary of state’s designation of the northwest runway scheme, including the process which led to the designation, was flawed by any legal error.”

The mood among the claimants I met in court 76 was that an appeal would be launched against the decision – possibly direct to the Supreme Court, “leapfrogging” the Court of Appeal.

Let us assume for now that any such challenge fails.

The judges pointed out that the bulldozers will stay silent until and unless a development consent order (DCO, in effect planning permission) is approved. The application will be scrutinised by independent inspectors and, the judges helpfully point out: “Any decision by the secretary of state to grant a DCO may also be the subject of a legal challenge.”

Heathrow airport and the Department for Transport are confident that the three years of deliberation by the Davies Commission, followed by two more years of further evaluation by government and seemingly endless consultations will demonstrate that MPs were well advised to vote overwhelmingly for expansion at Heathrow. (If only such unity could be brought to bear for Brexit...)

But note that no new full-length runways have been built in southeast England since the Second World War (London City, created in 1987, has only a short airstrip). In terms of passenger numbers, London is way ahead of the rest as global capital of aviation. If the market had its unconstrained way, Gatwick and Stansted would by now have two runways each, while Heathrow would be laying down its fourth.

The national benefits of aviation must be balanced against local and global concerns. But the political dimension could also be about to muscle its way in.

A future Labour government, supported by the London mayor, Sadiq Khan, might overturn the whole process; John McDonnell, shadow chancellor and MP for Heathrow (the airport lies within his Hayes and Harlington constituency), is an implacable opponent of expansion.

Alternatively Boris Johnson, MP for nearby Uxbridge and South Ruislip, would have no need to lie down in front of the bulldozers were he the prime minister with the power to bring back into play his absurd idea for a Thames Estuary airport.

During the decades of indecision, and of global ambition repeatedly sacrificed for local politics, airlines and air-traffic controllers have extracted an absurd amount of capacity out of Heathrow and Gatwick. The more expert they become at aviation alchemy, the longer that politicians can prevaricate.