(1)  A party to a negotiation for an agreement, or to an agreement, concerning a work group under this Subdivision may withdraw from the negotiation or agreement at any time by giving reasonable notice (in writing) to the other parties.

(2)  If a party withdraws from an agreement concerning a work group under this Subdivision –

(a) the other parties must negotiate a variation to the agreement in accordance with section 56 ; and

(b) the withdrawal does not affect the validity of the agreement between the other parties in the meantime.