(2)In any proceedings under this section to which the Central Government is a party, the Central Government may,—(a)if the patentee is a party to the proceedings, petition by way of counter-claim for revocation of the patent on any ground upon which a patent may be revoked under section 64; and(b)whether a patentee is or is not a party to the proceedings, put in issue the validity of the patent without petitioning for its revocation.
