Gatwick Airport has sparked a furious row over claims that rail services at the airport are so poor they are failing millions of passengers a year, writes our transport correspondent Mike Pearse.
It says unless things improve the airport will not meet its expected growth targets which will "impact on the UK economy." It also claims the airport lags behind most others in the world.
Managers say the Gatwick Express is not fit for airline passengers and the airport is demanding train company Southern "do something about it."
The Chief Commercial Officer Guy Stephenson says Chris Burchell, the Southern Managing Director knows "perfectly well services are are not up to scratch" and he must act.
The row centres on a decision to change the Gatwick Express trains and end a dedicated non-stop service to the airport from Victoria.
Until recently the Gatwick Express operated a dedicated fleet of carriages built in 2001 called Junipers. Now they have been replaced with Wessex Eclectics built thirteen years earlier.
It is claimed the substituted carriages have smaller doors and gangways and less space for luggage.
The decision was taken by the Government so at busy times of the day Gatwick Express trains could run to Brighton to ease overcrowding on one of the most congested routes in the country. It is not possible to run extra trains from the Sussex Coast to London because the tracks are full.
So the alternative was to extend twelve Gatwick Express trains at busy times down to the south coast. For technical reasons it was not possible to run the original Gatwick Express trains to Brighton so the fleet was changed.
But airport bosses say some of the extended trains are full by the time the reach Gatwickwith airport passengers having to suffer. The are demanding better trains and a dedicated service to the airport from London.
Guy Stephenson told Rail magazine "The needs of air passengers are very different from commuters, The ambiance is poor. It's not a modern environment. It is not fit for purpose and our customers expect better.
"The current Gatwick Express is not up to scratch, it is not suitable and Chris Burchell at Southern knows that perfectly well. Southern absolutely must do something about it because our customers expect and deserve an awful lot more."
Commuters on the Brighton line say they welcome the extended services because they provide them with more than six hundred extra seats on each train.
Chris Burchell at Southern says he understands the airport wants to expand and have a dedicated service.
But he says he has to balance the needs of the airport and a growing number of commuters from Brighton. He says the best option was to provide airport passengers with the best possible service but a busy times offer 6,000 more seats to Brighton line commuters.
Southern hit back at claims the trains are not up to standard. They say they have invested £14 million in improvements including CCTV, new seats and claim there is no less luggage space. They insist the trains are now more reliable than ever before and offer a good service.
Our Transport Correspondent Mike Pearse says "This is all about Gatwick trying to raise the debate ahead of a new franchise to run services on the Brighton line. It wants a dedicated service to be part of it.
"The new franchise will run services on the Gatwick Express, Southern and Thameslink. As part of the franchise it will be the Government who lay down what services run.
"Southern have done the best they can and it was the right decision to provide the extra seats to Brighton commuters. Many of the Gatwick Express trans ran half empty and that can not be right. The solution would be to provide extra capacity so that more trains can run then everyone would be happy but that is a decision for the future and would cost hundreds of millions of pounds.
"So for the time being Gatwick will continue to moan, passengers from Brighton will get the extra seats and Southern is caught up in the middle of the row."