Irrevocability of power expressed to be irrevocable

If a power of attorney given for valuable consideration is in the instrument creating the power expressed to be irrevocable, then, in favour of a purchaser, (a) the power shall not be revoked at any time, whether by anything done by the donor of the power without the concurrence of the donee of the power, or by the death, disability or bankruptcy of the donor of the power; and (b) any act done at any time by the donee of the power in pursuance of the power shall be as valid as if anything done by the donor of the power without the concurrence of the donee of the power, or the death, disability or bankruptcy of the donor of the power, had not been done or had not happened; and 77 (c) neither the donee of the power nor the purchaser shall at any time be prejudicially affected by notice of anything done by the donor of the power without the concurrence of the donee of the power, or of the death, disability or bankruptcy of the donor of the