Where, by reason that
the likely net sale value of the land would be insufficient to satisfy the
liability, an administrative authority determines that any prescribed charges,
or any charges the deferment of which has previously been allowed (whether
under this Act or the Pensioners (Rates Rebates and Deferments) Act 1966 4 ),
are payable as regards the land concerned but might not be recoverable,
despite being charged on the land, that administrative authority —
(a) may
decline to permit deferral in respect of that or any subsequent charged
period; but
(b) may
allow a rebate,
in respect of the
charged period.