Bosses at Gatwick Airport are laying out detailed plans for expansion to the Whitehall-appointed Airports Commission.
A second runway at the Sussex airport is one of the options for south east England airport expansion short-listed by the commission which is headed by former Financial Services Authority chief Sir Howard Davies.
Other options include a third runway at Heathrow and creating a new airport in the Thames Estuary.
Today Gatwick said its £7.8 billion second runway project was far cheaper and far more beneficial than Heathrow's.
They said the expansion: :
:: Will enable more people to fly to more destinations - 10 million more passengers each year will be able to travel with a second runway at Gatwick than with a third runway at Heathrow
:: Will generate more competition, keeping fares low, and delivering £40 billion more in economic benefits to the UK than expansion at Heathrow
:: A new runway at Gatwick can be delivered about five years earlier than a third runway at Heathrow at no additional cost or risk to the taxpayer
:: Expansion at Gatwick will deliver more than 120,000 jobs in London and south-east England, rebalancing the economy away from an overheated M4 corridor
:: Gatwick's location south of London means far fewer people will be affected by noise - a second runway at Gatwick would impact only 14,000 people compared with the 240,000 people impacted by noise from Heathrow today.
Gatwick chief executive Stewart Wingate said: “As we reach this critical point in the aviation debate it is clear that the Airports Commission has a very real choice to make: expand Gatwick and create genuine competition in the market with lower fares for everyone, or move back to a London airport market dominated by a single player and saddle the next generation with higher air fares.
"Why would you choose to fly a quarter of a million more planes every year over one of the world's most densely populated cities when instead you can fly them mostly over fields?
"Why tunnel part of the busiest motorway in Europe - the M25 - causing serious traffic disruption, when you can build on land already set aside for expansion? The choice is an obvious one. Expand the best and only deliverable option - Gatwick - and create a market that serves everyone."