The incident happened in Guildhall Street between 8.30pm and 8.45pm on Wednesday 18 August 2021.
It was reported that the victim, a woman in her 30s, confronted a man who was being verbally abusive to another member of the public.
The man reacted aggressively and is alleged to have attempted to hit her before spitting at her.
Anyone who recognises the man in the image is urged to call the appeal line on 01843 222289 quoting reference 46/151480/21. You can also call the independent charity Crimestoppers anonymously on 0800 555111 or complete the online form at www.crimestoppers-uk.org