Coming to an end of atonement, assuming the lead in reparations (10)

I believe the answer is:

expiration

'coming to an end' is the definition.

'atonement assuming the lead in reparations' is the subsidiary indication.
'atonement' becomes 'expiation' ('expiation' can be a synonym of 'atonement').
'assuming' is an insertion indicator.
'the lead in' says to take the initial letters.
The first letter of 'reparations' is 'r'.
'expiation' placed around 'r' is 'expiration'.

'of' is the link.

I've seen this clue in The Times.

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