4. An employer who has made a payment of statutory maternity pay may recover—
(i)the amount so paid, and
(ii)the amount determined in accordance with regulation 3,
by making one or more deductions from his contributions payments except where and insofar as—
(a)the contributions payments relate to earnings paid before the beginning of the income tax month in which the payment of statutory maternitypay was made;
(b)the contributions payments are made by him later than 6 years after the end of the tax year in which the payment of statutory maternity paywas made;
(c)the amount of the payment of statutory maternity pay or the amount determined in accordance with regulation 3 have been paid to him underregulation 5 by the Secretary of State; or
(d)the employer has made a request in writing under regulation 5 that the amount of the payment of statutory maternity pay or the amountdetermined in accordance with regulation 3 be paid to him and he has not received notification by the Secretary of State that the request is refused.