Continue to suppose parking not required (6)
I believe the answer is:
resume
'continue' is the definition.
(I know that resume is a type of continue)
'suppose parking not required' is the wordplay.
'suppose' becomes 'presume' (I've seen this before).
'parking' becomes 'p' (abbreviation on road signs).
'not required' indicates named letters should be taken away.
'presume' with 'p' taken out is 'RESUME'.
'to' acts as a link.
(Other definitions for resume that I've seen before include "Re-open" , "proceed" , "Continue - summary" , "Carry on (with something adjourned)" , "Short descriptive summary" .)