Irrevocable power of attorney means a power of attorney which a principle cannot revoke. In order to constitute an irrevocable power of attorney there must coexist with the power a beneficial interest in the subject thereof which is enforceable, or the power must be given as security for the payment of a sum of money other than that which arises as compensation through the exercise of the power, or as security for the performance of some act of value. It is also called as a power of attorney coupled with an interest.