Cheltenham sack boss Allner
The board of directors met to give Allner a unanimous vote of no confidence and both Allner and Davis have had their contracts terminated with immediate effect.
Davis was offered the role as caretaker manager but turned down the role and instead senior players Chris Banks and Mark Yates, as well as youth-team coach Bob Bloomer have been asked to take charge of first-team affairs pending the appointment of a new manager.
Allner took over the position from Steve Cotterill in the summer after he took charge of Division One side Stoke City and Cheltenham have suffered in the League ever since and are currently second from bottom in Division Two after being promoted the previous season via the Play-offs.
In a statement released by the club, said: "The board would like to place on record their appreciation for the tremendous amount of hard work that Graham and Mike have put in since taking over.
"This was always going to be a difficult task.
"In consideration, however, the board decided to act and make the change immediately."
Meanwhile, Banks has been forced to retire from full-time football after being advised by doctors that his long-standing knee injury would not recover sufficiently from damage sustained last March.
The Robins captain is the club's longest-serving player, having witnessed the Whaddon Road club's rise from the Dr. Martens Premier Division to Division Two.