GATWICK bosses are launching a formal challenge over the Airports Commission inquiry which they claim was “heavily biased” in favour of rivals Heathrow.

Key to their challenge is the assertion that the report significantly underestimated the number of passengers who will fly out of the airport in future years.

The Sir Howard Davies commission used statistics from the Department for Transport which estimated 40 million people would use Gatwick by 2024.

However, airport bosses claim they will see that number this year.

Gatwick bosses have also questioned the “flawed” assumption that most long haul traffic will use an expanded Heathrow instead of the Sussex airport.

Bosses are also expected to challenge the commission over allegations it played down the environmental and noise impact of the Heathrow proposal.

Last week the Airports Commission decided that Heathrow application was the better of the two and recommended MPs approve the scheme.

The Government is expected to make a final decision by the end of the year.