In the 53-second clip, posted to Twitter by imjustbrum, the reporter becomes fed up with the man who he accuses of repeatedly walking into the back of his shot, asking him if he has a job and whether it's at McDonald's or Footlocker.
An ITV spokesman apologised, and said Mr Watkinson had been spoken to.
He said: “ITV has spoken to the reporter and the matter is being dealt with internally.
“We apologise for any offence the comments have caused and will not be commenting further at this time.”
During his potty-mouthed rant, Mr Watkinson said: "I'm not a higher class than you mate, I'm just trying to do a job – have you got a job?"
When the man replied "yeah I do", the reporter retorted: "Well go and f***ing do it and I won't come into your workplace and start ****ing with ya."
Mr Watkinson, after being told to "stop being rude", replied: "If you get behind me again I will ****ing bang you out, do you understand me?"
"Why don't you go and get a job and then I will come behind you and start behind an idiot?" he asked, while performing a mocking dance.
"Where do you work? Footlocker or McDonald's?," he continued, prompting a response of: "Nothing wrong with that."
In the final part of the clip he's heard asking: "How about sorry for trying to mess up my work? How about that? Do you know how hard it is to broadcast live to half a million people?
"Do you know how hard it is to concentrate? It's quite hard without someone in the background going 'ooooh I want to be on TV'."