cast a slur

See: smear
References in classic literature ?
The metaphor irritated Philip, because it assumed for the speaker a romantic attitude and cast a slur upon the position which Philip instinctively felt had more to say for it than he could think of at the moment.
Health Minister John Hutton said the Tories cast a slur on "the vast majority of hard-working staff in the NHS".
JUSTICE Minister Michael McDowell last night rejected claims he had cast a slur on the Garda by proposing a ban on officers giving information to journalists.