Crown representative’s lad involved with union letter (4,10)

I believe the answer is:

lord lieutenant

'crown representative's' is the definition.
(I've seen this before)

'lad involved with union letter' is the wordplay.
'involved with' is an anagram indicator (involved can mean confusing or complex).
'union'+'letter'='unionletter'
'lad' mixed up with 'unionletter' makes 'LORD LIEUTENANT'.

(Another definition for lord lieutenant that I've seen is " Crown representative".)

I've seen this clue in The Times.

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