Heathrow boss urges Boris Johnson to back third runway

Heathrow has appealed to the London mayor, Boris Johnson, to back its campaign for a third runway, ahead of the possible dismissal of his own Thames estuary scheme from consideration by the Airports Commission.

In an open letter to the mayor, Heathrow's recently appointed chief executive, John Holland-Kaye, reminds Johnson that they share the same belief that only a large, hub airport can provide the scale and range of global flights that the economy needs.

Johnson has repeatedly stressed the need for "hub airport capacity", in contrast to the arguments of Gatwick – the rival contender for expansion.

Holland-Kaye wrote to Johnson: "We have nothing against Gatwick but you have rightly identified that its claim that it can deliver the same benefits as a hub airport is 'a sham, a snare and a delusion'."

While Johnson has been forthright on Gatwick, he has been at least equally outspoken on Heathrow's claims to be able to expand enough to meet future demand. Last year he said: "Anyone who believes there would be the space to do that at Heathrow, which already blights the lives of hundreds of thousands of Londoners, is quite simply crackers."

The Airports Commission, led by Howard Davies, is expected to announce next week whether it will add the Thames estuary plan to a shortlist of options, which currently contains the proposal for extra runways at either Heathrow or Gatwick.

The situation has been complicated by the decision of Johnson to apply to become MP for Uxbridge, near Heathrow in west London. Heathrow fears that if Davies finally gives an official rejection to the Thames estuary, the mayor could throw his weight behind Gatwick – although sources close to Johnson suggest that is unlikely.

Holland-Kaye's letter reminds the mayor that an expanded Heathrow would "create over 100,000 new jobs, many of which will be in your proposed constituency of Uxbridge".

He added: "I urge you to maintain your support for a successful hub airport. Any other choice would be a betrayal of the case that you have made so effectively over the last three years."

A Gatwick spokesperson said the airport would await the outcome of the Airports Commission's decision on the estuary option before commenting, and would write privately to the mayor if his plan was eliminated, "giving him the respect he deserves".

However, she added: "Building a second runway at Gatwick will deliver two world-class airports and competition, which will lead to lower air fares and greater choice for passengers and business. It will also help make Heathrow better; their expensive charges would come down and they would be better incentivised to alleviate "Heathrow hassle", which has blighted British travellers for years.

She continued: "We support competition, reduced fares and two world-class airports serving the UK as a whole. As the mayor himself said: 'Why on earth entrench a huge planning error and expand Heathrow and consign future generations to misery?'"

A spokesperson for the mayor said: "The mayor is awaiting the decision of the Airports Commission on shortlisting an estuary airport. It is the only credible option and the only one that gives us both the global and national connectivity we need in the medium and longer term."