41(1)If it appears to the Treasury that there has been a change in the value of money since the last relevant date, they may by regulations substitute for the sums for the time being specified in paragraphs 39(2) and 40(2) such other sums as appear to them to be justified by the change.
(2)In sub-paragraph (1) “relevant date” means—
(a)the date on which this Act is passed, and
(b)each date on which the power conferred by that sub-paragraph has been exercised.
(3)Regulations under this paragraph do not apply to any failure or obstruction which began before the date on which they come into force.