(a) On application to the District Court by a competent authority on whose application the District Court has made an antecedent order, the Court may, to secure payments under the antecedent order, if it is satisfied that the liable relative is a person to whom earnings fall to be paid, make an attachment of earnings order.
(b) References in paragraph (a) to an antecedent order made by the District Court shall include references to such an order made, varied or affirmed on appeal from that Court.
(2) An attachment of earnings order shall be an order directed to a person who (at the time of the making of the order or at any time thereafter) has the liable relative in his employment and shall operate as a direction to that person to make, at such times as may be specified in the order, periodical deductions of such amounts (specified in the order) as may be appropriate, having regard to the normal deduction rate (within the meaning of subsection (4)(a)) and the protected earning