Criticises financial centre; forgets what to say about it (7)
I believe the answer is:
decries
'criticises' is the definition.
(to decry something is to denounce or criticise it)
'financial centre forgets what to say about it' is the wordplay.
'financial centre' becomes 'EC' (EC is the postcode for the City of London).
'forgets what to say' becomes 'dries' (as in drying up when speaking).
'about it' indicates putting letters inside.
'ec' put into 'dries' is 'DECRIES'.
(Other definitions for decries that I've seen before include "Publicly denounces" , "Condemns, excoriates" .)