Fewer working class (6)

I believe the answer is:

lesson

'class' is the definition.
(I've seen this before)

'fewer working' is the wordplay.
'fewer' becomes 'less' ('less' is associated in meaning with 'fewer').
'working' becomes 'on'.
'less'+'on'='LESSON'

(Other definitions for lesson that I've seen before include "Class session or reading from Bible" , "See 1" , "Severe reproof" , "Teaching period" , "warning message" .)

I've seen this clue in The Telegraph and The Times.

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