3.—(1) Any contract of employment under which a betting worker who satisfies paragraph 2(2)(a) was employed on the day before the commencement date is unenforceable to the extent that it—N.I.
(a)requires the betting worker to do betting work on Sunday on or after that date; or
(b)requires the employer to provide the betting worker with betting work on Sunday on or after that date.
(2) Subject to paragraph (3), any agreement entered into after the commencement date between a protected betting worker and his employer is unenforceable to the extent that it—
(a)requires the betting worker to do betting work on Sunday; or
(b)requires the employer to provide the betting worker with betting work on Sunday.
(3) Where, after giving an opting-in notice, a protected betting worker expressly agrees with his employer to do betting work on Sunday or on a particular Sunday (and so ceases to be protected), his contract of employment shall be taken to be varied to the extent necessary to give effect to the terms of the agreement.
(4) For the purposes of paragraph 2(2)(b), the appropriate date in relation to this paragraph is the day on which the agreement is entered into.]