Patronise lecture by Spooner's municipal party? (4,4,2)

I believe the answer is:

talk down to

'spooner's municipal party?' is the definition.
I know nothing about this answer so I can't judge whether this works.

'patronise lecture by' is the wordplay.
'patronise' becomes 'downto' (I am not sure about this - if you are sure you should believe this answer much more).
'lecture' becomes 'talk' (synonyms).
'by' means one lot of letters go next to another.
'downto' put after 'talk' is 'TALK DOWN TO'.

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app