Ms Alexander will want to ensure the Gatwick expansion project is watertight, as it could face a legal challenge once given a formal greenlight, given opposition from local communities and environmental groups.
The Government has said that sustainable aviation fuel means airport enlargements do not derail net zero targets, and as such it has also backed a new runway at Gatwick's bigger rival, Heathrow.
Gatwick's privately financed project would see it move the emergency runway 12 metres north, enabling it to be used for departures of narrow-bodied planes, such as Airbus A320s and Boeing 737s.
Ms Alexander extended the deadline for a final decision by nine months to October 27 after a report from planning inspectors flagged up major concerns about the impact on local traffic, noise and air quality.
Siân Berry, Green MP for Brighton Pavilion, said: “Only one day after receiving critical advice from its own climate advisors on the need to lower flying demand, ministers decide to support yet more unnecessary expansion for the benefit of wealthy investors.”.
