Consent to, allow (6)
I believe the answer is:
permit
I believe this clue is a double definition.
'consent to' is the first definition.
(I've seen this before)
'allow' is the second definition.
(synonyms)
(Other definitions for permit that I've seen before include "Licence -- license" , "Allow; make possible" , "Let; enabling document" , "Official document giving authorisation" , "Officially allow" .)