What the advocate assumes is put on at the Palace (5,5)

'the palace' is the definition.
Both the definition and answer are singular nouns.
Maybe there's a link between them I don't understand?

'what the advocate assumes is put on' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'on' could be 're' ('on' can be mean 'with reference to') and 're' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

'at' acts as a link.

Can you help me to learn more?