22.Section 4 provides the licensing authority with the discretion to revoke a licence on particular grounds, including where the local authority is no longer satisfied that the licensee is a suitable person to carry on the business as a scrap metal dealer. The revocation of a licence can only be carried out by a local authority as the licensing authority. The section also allows the licensing authority to vary a licence, imposing the conditions stipulated in section 3, if the licensee or a site manager is convicted of a relevant offence. This power includes the power to impose conditions pending an appeal, where a licensee is appealing a decision to revoke a licence.