The most built-up BBC party repeatedly curtailed (8)

I believe the answer is:

beefiest

'the most built-up' is the definition.
(beefy can mean built-up or muscular)

'bbc party repeatedly curtailed' is the wordplay.
I cannot quite understand how this works, but
'party' could be 'bee' (I've seen this in another clue) and 'bee' is present in the answer.
This explanation may well be incorrect...

(Another definition for beefiest that I've seen is " Superlatively massive".)

I've seen this clue in The Times.

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