High Court Clears Gatwick Airport Expansion. Campaigners Vow to Appeal.

High Court judge Mr Justice Mould issued a 100-page ruling Tuesday dismissing both challenges brought by campaign group Communities Against Gatwick Noise Emissions (CAGNE) and campaigner Peter Barclay, chairman of the Gatwick Area Conservation Campaign.

The core legal argument was that Transport Secretary Heidi Alexander had failed to properly assess the climate impact of the expansion before approving it in September. Mould rejected that framing flatly.

He found Alexander's conclusions "rational and supported by proper, adequate and intelligible reasons," according to all four sources covering the ruling. He also ruled it was "neither illogical nor contradictory" for Alexander to acknowledge the development would not "fully contribute to the UK's trajectory towards net zero" while still approving it, because that finding alone was not enough to kill the project under the law.

A Gatwick Airport spokesperson called the judgment a "victory for common sense," according to BBC News and City AM. The Department for Transport said the project "balances our environmental and climate commitments with huge economic benefits."

The £2.2 billion plan moves Gatwick's existing emergency runway 12 metres north, converting it into a fully operational strip used for departures of smaller short-haul aircraft. No new runway is being built. The physical infrastructure already exists.

According to City AM, the expansion could be complete by 2029. Gatwick Airport Limited says the project will create 14,000 jobs and deliver a £1 billion annual boost to the UK economy. The airport's current capacity stands at roughly 280,000 flights per year. The BBC reported that capacity would rise to 389,000 flights annually by the late 2030s.

Travel journalist Simon Calder described it to BBC News as "the first meaningful airport expansion in decades," calling it "nothing but an overwhelming positive" for the economy of the Gatwick area and for travelers in southeast England.

Before dismissing the concerns as legally insufficient, Mould's ruling actually acknowledged significant environmental trade-offs. Alexander herself placed "moderate adverse weight" against the project because of its climate effects. That is not a trivial concession. It means the government's own analysis found real harm, then decided economic need outweighed it.

Cagne's objections went beyond climate. According to City AM, campaigners argued the government had not laid out a feasible means of funding essential infrastructure or improving local sewage treatment in the expansion blueprint. BBC News reported that affected communities cited noise, air quality, and emissions as concerns alongside the infrastructure gaps.

Peter Barclay noted that both the independent Climate Change Committee and the Parliamentary Environmental Audit Committee had recommended against airport expansion. "The expansion decision ignores that advice," he said, according to BBC News.

Those are credible institutions. Their recommendations don't have legal force here, but dismissing them entirely would be dishonest. Communities in Kent, Surrey and Sussex funded this litigation themselves. It wasn't a stunt by a fringe group.

The legal question before Mould was not whether the expansion is wise policy. It was whether Alexander followed the law when she approved it.

She did. She weighed the climate effects, assigned them adverse weight, and still concluded the socio-economic case was stronger. That is a judgment call the law allows a Secretary of State to make. Judges do not substitute their own policy preferences; they check whether the decision-maker's reasoning was rational and lawful. Mould found it was, according to Morningstar and ITV News.

The Planning Inspectorate had initially rejected Gatwick's application. City AM reported it found the original plans failed to mitigate noise sufficiently and didn't adequately account for higher passenger volumes. Alexander overrode that rejection. Mould found her reasoning for doing so was sound.

Cagne said in a statement it would not accept the ruling "as the final word" and that its legal team would consider an appeal, according to BBC News and ITV News.

The unresolved question is whether an appeal would go anywhere. Mould's 100-page judgment is detailed and deferential to the Secretary of State's statutory authority, the standard most likely to survive appellate scrutiny. An appeal would need to identify a specific legal error in his reasoning, not simply argue the decision was wrong on the merits.

If no appeal succeeds or is granted permission, construction groundwork could begin ahead of the projected 2029 completion. Whether the government's infrastructure and sewage commitments—the concerns Mould did not appear to fully resolve on the merits—actually materialize once shovels hit the ground is the question local communities will be watching most closely.