The race to secure backing for airport expansion is down to two after “Boris Island” was ruled out.

Gatwick Airport is now competing with Heathrow to win over the Airports Commission for a new runway.

The commission, which will make a recommendation to government in the next parliament, was not shortlisted Boris Johnson’s Thames Estuary airport option.

Gatwick bosses said the expansion in Sussex would mean lower fares and greater passenger choice.

Chief executive Stewart Wingate said: “This is an important juncture in the aviation debate because now Britain’s choice is clear; expand Gatwick and support genuine competition, lower fares and greater choice for passengers or expand Heathrow and return to the stale monopoly of the past and watch the cost of going on holiday, travelling for business and exporting goods and service go up.

“We believe Gatwick has the strongest case. It is the only option left on the table that can be delivered with more certainty than either of the Heathrow options, and it can be delivered without the significant environmental impacts expansion at Heathrow would inflict on London. It can be delivered faster than any other option, and at low cost and low risk.

“Furthermore, expanding Gatwick will ensure the UK is served by two successful world class airports. It can liberate hub capacity at Heathrow and open up the opportunities for affordable long haul travel to emerging markets for the benefit of everyone, made possible by new generation of aircraft such as the Dreamliner.”

Gatwick says it will secure £7.8 billion funding for the new runway, whereas Heathrow’s will cost £15.6 billion and require public funding.

The airport also says it will deliver around £90 billion of economic benefits and create around 120,000 jobs.