A support post comprising first and second elongate members, a ceiling engaging member at the upper end of the first elongate member and a floor engaging member at the lower end of the second elongate member. A spring biases the ceiling engaging member away from the upper end of the first elongate member. A lock maintains the spring in a compressed configuration. When in its unlocked position the lock releases the spring and permits it to apply a biasing force to the ceiling engaging member, urging the ceiling engaging member away from the upper end of the first elongate member. A latch is secured to the first elongate member and permits telescopic movement between the elongate members when said lock is in its locked position. The latch engages the second elongate member when the lock is in its unlocked position and resists relative telescopic movement between the elongate members.