The ability of regional airports to compete and grow would be threatened if Heathrow is allowed to expand and dominate the UK aviation market.
The claim comes from rival Gatwick in its latest submission to the Airports Commission.
Gatwick says a third runway at Heathrow would “threaten the commercial viability” of other UK airports by reducing choice and giving the London hub more market power.
However, building a second runway at Gatwick would generate more “rigorous competition” between airports in London and the southeast, help regional airports to compete, specialise and grow and would give passengers from the UK regions more choice of flights to London, helping to reduce fares, the submission claims.
Manchester, Edinburgh, Newcastle and Birmingham airports are among those building long-haul networks with direct flights, a trend likely to continue as the next generation of aircraft such as the Boeing 787 Dreamliner makes such routes increasingly viable.
Hub airports in the Middle East and Turkey create opportunities for passengers flying from airports outside London to fly to the other side of the globe with a single change of flight.
Gatwick chief executive Stewart Wingate said: “A new runway at Heathrow would give the airport too much market power. However, if Gatwick built a second runway, it could compete more vigorously with two-runway Heathrow, which would deliver benefits for both consumers and other UK airports.”
Birmingham airport chief executive Paul Kehoe said: “We need a network of national airports across the country, with healthy competition driving up standards and choice for passengers.
“Long-haul airports across the country, like Birmingham, play a central role in providing this choice, and the global connectivity we deliver is essential for supporting the growth of our regions.
“This would be threatened if we were to allow one single hub to dominate the market.”