(3)It is hereby declared that a person who may become accountable as trustee of a settlement for estate duty payable by virtue of section 11 on property which is or has been comprised in the settlement has a lien for the prospective amount of the duty and the costs in respect thereof on any property in his hands which is so comprised.Explanation. - References in this section to the prospective amount of any duty are to be taken as referring to the prospective amount of the duty on the assumption that it will become chargeable.
