As JetBlue Airways’ planned launch date for Atlanta service nears, the airline is in a dispute with Hartsfield-Jackson International Airport over which gates it will use.

In a letter to the Federal Aviation Administration, JetBlue said it is “in the position of having to decide whether to postpone the March 30 service launch at the airport, which would negatively affect more than 50,000 customers, or proceed in rushed fashion to ready gate and support space that is less optimal from an operational and a commercial perspective.”

New York-based JetBlue plans to start Atlanta-Boston flights on March 30. In the letter to the FAA, obtained by The Atlanta Journal-Constitution, the airline said it had expected to be able to operate out of Concourse E.

But on Feb. 14, six weeks before the flights are scheduled to start, the airport sent a proposal for JetBlue to split its five daily flights between gates on Concourse D and Concourse E.

Concourse E, built in 1994 for international flights, is more spacious than the airport's older Concourses T, A, B, C and D.

According to the airport, the priority on Concourses E and F is international flights.

In a letter last June, JetBlue's vice president of network planning, Dave Clark, wrote to Hartsfield-Jackson general manager Roosevelt Council that "it's clear that the existing common use gates at the end of the D Concourse are not satisfactory to serve the aircraft and higher end business and leisure travelers that JetBlue is targeting in the Atlanta market."

JetBlue contends in the letter to the FAA that it had been assured by Council it could operate out of Concourse E or Concourse F, a newer international gate complex, and that was a condition for its service launch in Atlanta.

JetBlue has already sold more than 50,000 tickets, according to the letter. The airline plans to eventually add flights between Atlanta and New York's John F. Kennedy International, Orlando and Fort Lauderdale.

The airline says in the letter that it must now complete construction of support space for its operations in the next three weeks, and said all construction plans had previously been for Concourse E.

In the letter, JetBlue asked the FAA to intervene, contending: "It appears that actions have been taken behind the scenes, at this late hour, to try to restrict competition at ATL."

JetBlue wrote that the situation is "indicative of a larger public policy issue," with four mega-carriers dominating the industry and "significant obstacles for smaller airlines to break into markets."

The FAA has not yet responded to the letter. Hartsfield-Jackson officials declined to comment on the letter.