A sealing assembly including a seal element at least partially formed from a shape memory material. The shape memory material urges the seal element to revert to an original shape upon exposure to a transition stimulus. The seal element is operatively arranged for sealing against a downhole structure when in the original shape. An interlock mechanism is included for holding the seal element in a deformed position in which the seal element is not able to seal against the downhole structure even after exposure to the transition stimulus. A method of setting a downhole sealing assembly is also included.
