Shocked customers watched on as an argument broke out between a customer and the owner of the Clubhouse on London Road on Thursday night.
Witnesses said that following the argument over a political disagreement, the owner then drunkenly called the customer the N-word.
An apology from the Clubhouse's manager was swiftly posted on the bar's Facebook page over the owner's 'improper language'.
But now the owner, Adrian Keogh, has taken to Facebook himself to apologise for his actions and revealed he's now enrolled in an Equality and Diversity course.
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Mr Keogh posted: "I would like to apologize for my language and actions of Thursday. Firstly to the people immediately present, my language was completely unacceptable, and I'm embarrassed to hear what I said, I genuinely apologize to you.
"To my staff and customers, I have unfairly brought an ugly element in to a venue you work hard in and support.
"I see the hurt my words and actions have caused and I don't want to be the person who causes such unnecessary anguish or harm.
"I'm deeply upset by my actions, I've spent the last 1.5 days trying to understand why I would behave in this manor, and how I prevent this ever occurring again.
"I have taken advice and much deserved criticism from friends and acquaintances, as a result I have enrolled in a course for Equality and Diversity, the person who advised this said it greatly helped him, and I'm committed to this helping me understand my character faults, and becoming a much more compassionate individual.
"Secondly, I've taken advice on my alcohol consumption, and committed to a program to prevent me being in this state of inebriation again."
Outraged customers took to Facebook following the incident to leave furious reviews; branding the racist attack 'completely unacceptable'.
One shocked customer wrote: "Racist landlord who thinks it’s ok to call Black Women the N word in 2018 - rating should be minus points. Boycott and stay away.
"Sounds made up doesn't it, I only wish it was, but I know and care about the women that this happened to.
"They wouldn't make up something this serious. How dare you treat people like this?? Public apology needed now! There's no excuse for racism EVER. I join the boycott of this venue."
Some customers have called on Mr Keogh to step down from his position following his actions.
However other customers have praised the owner for his 'courage' in admitting his mistakes and addressing them.
"One of the aspects I've always been most proud of is the widely diverse customer base we have, it greatly adds to our venue, and I apologise again for my actions impacting this," Mr Keogh continued.
I understand some will find my behaviour and language completely unforgivable, I regret this deeply, however respect you for it. One day I hope I get the opportunity to prove my genuinely good character to you."