Poor old gent as Victorian prime minister (9)
I believe the answer is:
gladstone
'prime minister' is the definition.
(William Ewart Gladstone Prime Minister 1868-1894)
'poor old gent as' is the wordplay.
'poor' indicates anagramming the letters.
'old'+'gent'+'as'='oldgentas'
'oldgentas' anagrammed gives 'GLADSTONE'.
'victorian' acts as a link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for gladstone that I've seen before include "British statesman, four times PM, d. 1898" , "5,27 [PRIME MINISTER]" , "PM no longer" , "Tangled so like hinged case" , "Old English P.M. or kind of bag" .)