This section has effect where—
a parental compensation order has been made in favour of any person in respect of any taking or loss of property or damage to it; and
a claim by him in civil proceedings for damages in respect of the taking, loss or damage is then to be determined.
The damages in the civil proceedings shall be assessed without regard to the parental compensation order, but the claimant may recover only an amount equal to the aggregate of the following—
any amount by which they exceed the compensation; and
a sum equal to any portion of the compensation which he fails to recover.
The claimant may not enforce the judgment, so far as it relates to such a sum as is mentioned in subsection (2)(b) above, without the permission of the court.