Conservative turncoat in terribly miserable old political group (7,9)

'terribly miserable old political group' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'conservative turncoat' is the wordplay.
I cannot really understand how this works, but
'conservative' could be 'c' (UK political abbreviation) and 'c' is located in the answer.
'turncoat' could be 'rat' (I've seen this in another clue) and 'rat' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

'in' acts as a link.

Can you help me to learn more?