enter in relation to a person in possession of an entry clearance 321. A person seeking leave to enter the United Kingdom who holds an entry clearance which was duly issued to him and is still current may be refused leave to enter only where the Immigration Officer is satisfied that: (i) False representations were made or false documents or information were submitted (whether or not material to the application, and whether or not to the holder's knowledge), or material facts were not disclosed, in relation to the application for entry clearance; or in order to obtain documents from the Secretary of State or a third party required in support of the application. (ii) a change of circumstances since it was issued has removed the basis of the holder's claim to admission, except where the change of circumstances amounts solely to the person becoming over age for entry in one of the categories contained in paragraphs 296-316 of these Rules since the issue of the entry clearance; or (iii) refusal is justified on grounds of restricted return ability; on medical grounds; on grounds of criminal record; because the person seeking leave to enter is the subject of a deportation order or because exclusion would be conducive to the public good. Grounds on which leave to enter or remain which is in force is to be cancelled at port or while the holder is outside the United Kingdom 321A. The following grounds for the cancellation of a person's leave to enter