Queen attending summit in States disheartened, they say (8)

'they say' is the definition.
(people who say things)

'queen attending summit in states disheartened' is the wordplay.
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'attending' is a charade indicator (letters next to each other).
'summit' becomes 'peak' (mountain peak).
'in' means one lot of letters goes inside another.
'disheartened' says to hollow out the word (remove centre letters).
'states' with its middle taken out is 'ss'.
'er' after 'peak' is 'peaker'.
'peaker' put within 'ss' is 'SPEAKERS'.