The future of the only air link between Leeds-Bradford International Airport and London has been called into question by airline bosses.
Sir Michael Bishop, chairman of airline BMI - the only airline to fly between Leeds-Bradford and Heathrow - has called into question the cost of airport charges at the Yeadon airport and described them as an issue that needs to be resolved in order to maintain the service.
A letter from Sir Michael to Michael Goodwin, chairman of Leeds-Bradford, lists a series of concerns regarding the Heathrow service.
In the letter Sir Michael says: "These fees will need to drop significantly in cash terms for the service to remain viable.
"Airport charges are a big percentage of the cost base of any short haul route and remain higher at Leeds Bradford than we pay at any other airports in our network.
"We note that the airport has been recently sold at a premium and its new owners will be keen to re-coup their investment.
"Therefore this is a serious issue and we did write to the financial advisors handling the bid process making them aware of our requirement to pay considerably less if the service was to be maintained."
Sir Michael also mentions that other regional airports have gained financial support from "local interests", desperate to retain the link to Heathrow and suggested this as an option for Leeds-Bradford.
He also urged business and leisure groups to "use the service or lose it".
The issue is to be discussed at a Leeds-Bradford Airport Consultative Committee meeting tomorrow. Sir Michael had been responding to a letter from Mr Goodwin, expressing concerns that the connection may be under threat due to the knock on effect of increased charges at Heathrow.
Peter Willis, operations director at Leeds-Bradford played down the speculation that the service could be lost between the region and Heathrow.
He said that the level of charges would be discussed between both parties - although a settlement was some way from being established.
He also said that passenger levels on the London Heathrow service "went through peaks and troughs".
BMI operates several services a day between Leeds-Bradford and Heathrow.