Former Salisbury City Councillor Mark Mewse, 64, has stepped down, offering heartfelt apologies to the residents he once served.
Mewse was found guilty of harassment at Salisbury Magistrates Court last month.
The hearing heard details of Mewse's attempts to win back an ex's affections by buying gifts her cats.
The court heard how Mewse unleashed a barrage of messages upon his former partner.
Mewse, of Cranesbridge Road, was the councillor for Stratford and St Francis on Salisbury City Council.
A by-election will be held to elect a new councillor.