An actuating device is provided for moving a closure panel between an open position spaced apart from a vehicle body and a closed position abutting the vehicle body to close an access opening thereof. The actuating device includes a telescopic arm having a first member coupled to one of the closure panel and the vehicle body and a second member coupled to the other of the closure panel and the vehicle body. The first and second members are slidable relative to one another to move the actuating device between a retracted position corresponding with the closed position and an extended position corresponding with the open position. A screw is rotatable relative to the first member. The screw includes a cavity formed therewithin. A nut is secured to the second member and threadingly engages the screw such that rotation of the screw moves the second member towards and away from the first member to move the actuating device between the respective retracted and extended positions. A gas spring is at least partially disposed within the cavity of the screw for urging the actuating device into the extended position to move the closure panel into the open position.