Delta has told staff they can no longer use their luxury Sky Clubs due to crowding

A woman sits on a sofa on the phone, a suitcase beside her. (Credit: Wera Rodsawang - Getty Images)

Staff at one of the U.S.'s biggest airlines have been told they can no longer make use of its luxury airport lounges due to overcrowding.

Delta Air Lines has banned staff from using its Sky Clubs when employees are flying standby with company travel privileges — even though they have to pay for access. They've also been booted out of Sky Clubs when traveling for company business, CNBC reported.