31(1)
A chief officer of police shall not refuse to grant or renew, and shall not revoke, a firearm certificate in respect of a prohibited weapon or prohibited ammunition if the applicant for the certificate is for the time being authorised by the Defence Council under section 5 of this Act to have possession of that weapon or ammunition.
31(2)
Where an authority of the Defence Council under that section to have possession of, or to purchase or acquire, a prohibited weapon or prohibited ammunition is revoked, the firearm certificate relating to that weapon or ammunition shall be revoked or varied accordingly by the chief officer of police by whom it was granted.