Gatwick urged a “more proportionate approach” to business rates as passenger numbers fell by almost 5% in the first half of the year amid the Middle East conflict.
The airport also attributed the year on year decline to 19.1 million travellers on “capacity restrictions” by some low-cost carriers.
However, revenue grew by 4.8% in the six months to £515.2 million with earnings (ebitda) increasing by 5.5% to £276.5 million in what was described as a “solid operational and financial performance”.
Gatwick said: “Whilst passenger numbers were impacted by the conflict in the Middle East, demand for travel remains strong, as evidenced by the successful launches of services operated from seven new carriers, including Jet2, Air France, Condor and Eurowings, and a significant increase in the number of carriers serving the airport.
“A further two airlines - Air Zimbabwe and Air Arabia - also launched in the second half of this year.”
Chief executive Pierre Hugues-Schmit said: "As we look ahead, it is important that the wider policy environment continues to support businesses that are investing for the long term.
“In the build-up to the budget therefore, our key ask of government is for a more stable and proportionate approach on key issues such as business rates, to ensure the UK aviation sector remains competitive and affordable for passengers."
The UK’s second largest airport now serves more than 231 destinations with over 60 airlines.
Passengers passed through security in five minutes or less 95% of the time, while the airport achieved 99% of its agreed passenger service measures in the period.
The first half results came after Gatwick received final approval to bring its stand-by northern runway into regular operation after an eight-year legal and planning process.
A £1.9 billion capital investment scheme also continues to progress, with a £140 million Pier 6 western extension remaining on schedule for completion in early 2027.
Hugues-Schmit said: “Despite a challenging geopolitical and economic backdrop, London Gatwick has continued to perform well, grow its network and deliver a world-class service for passengers.
"We are also excited about our longer-term growth opportunities and with the legal process for the northern runway programme now complete, we can turn our focus from planning to detailed design work and delivery.
“This is one of the UK’s largest privately financed infrastructure projects and, alongside our existing £1.9 billion capital investment programme, demonstrates our confidence in Gatwick’s future and our commitment to continuing to invest in our infrastructure while supporting jobs, trade, tourism and the regional economy."