What Liberal Democrat must be to be seen as moral and creditable? (10)

'creditable?' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives can occasionally mean the same thing.

'what liberal democrat must be to be seen as moral and' is the wordplay.
I cannot really see how this works, but
'democrat' could be 'd' and 'd' is found within the answer.
'be' could be 'am' and 'am' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
'as' could be 'aa' (two letter A's) and 'aa' is found in the remaining letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?