Clifford Chance (CC) is this week moving to reassure top clients they have not been over-billed by its US arm – as the Manhattan district attorney (DA) confirmed that any firms found to have ‘padded’ their bills could face prosecution.

The move by CC follows the highly embarrassing leak of an internal memo in which a group of New York associates warned that an annual billing target of 2,420 hours “encouraged” them to “pad” their hours.