8.—(1) M or, as the case may be, P may vary the period or periods during which they intend to claim statutory shared parental pay (birth) by notice in writing given to the employer who will be liable to pay that pay to M or P at least 8 weeks before the beginning of the first period specified in that notice.
(2) M may vary the number of weeks in respect of which M intends to claim statutory shared parental pay (birth) by notice in writing given to the employer who will be liable to pay statutory shared parental pay (birth) to M—
(a)of the number of weeks during which M and P have exercised, or intend to exercise, an entitlement to statutory shared parental pay (birth) in respect of C; and
(b)which is accompanied by a written declaration signed by P who in connection with M's claim is required to satisfy the conditions specified in regulation 4(3) that P consents to that variation.
(3) P may vary the number of weeks in respect of which P intends to claim statutory shared parental pay (birth) by notice in writing given to the employer who will be liable to pay statutory shared parental pay (birth) to P—
(a)of the number of weeks during which P and M have exercised, or intend to exercise, an entitlement to statutory shared parental pay (birth) in respect of C; and
(b)which is accompanied by a written declaration by M who in connection with P's claim is required to satisfy the conditions specified in regulation 5(3) that M consents to that variation.