Tommy told listeners how he had no choice but to work part-time as a taxi driver since he does not get enough work on Fair City to sustain him.
Padraig Murray, president of actors' union Equity, said a lot of other Fair City actors had worked as taxi drivers part-time to make ends meet as well.
"The amount of work the actors are getting is around 20 weeks in the year which is not an awful lot, and they're not being paid a fortune either.
"If someone sees an actor on television they automatically assume that they must be earning a fortune but the majority of actors are working for minimum rates.
"The amount you're paid depends on your standing - how long you've been in the series. You could be paid a daily rate, a weekly rate or other rates, it depends.
"Around 50 to 60pc of actors on Fair City are double-jobbing. They're doing everything from working in restaurants, to building, to driving taxis, and then they're working in other areas of the arts like from the administrative side and teaching."
An RTE spokesperson said it did not comment on actors' salaries. "Like all Fair City actors, Tommy is contracted to work on the soap," she added.
An angry cabbie, known as 'Tony', contacted RTE's Liveline last Monday to air his grievances about actor Tommy appearing to skip the queue at a taxi rank to pick up a fare.
"When [Tommy] dropped his passengers, people proceeded over to his car and he took them, instead of directing them to the taxis which is what we do. I knocked on his driver's window and asked him what he was doing, that there was a queue outside and he screamed at me: 'They asked for me'."
Tommy said he, like "every actor," had to work in another job alongside Fair City and he said "people think I'm on the telly and I'm rich."
Tommy admitted that he should have queued up to pick up passengers.
Tommy said on Liveline: "First of all let me state from the outset that, yeah, I was wrong.
"But you are working in a recession and every driver out there knows. People think I'm on the telly and I'm rich. Every actor has another job.
"I wish the taxi regulator would give me my €6,000 for my licence back because to be honest I hate it."
A taxi union official has blamed double-jobbing taxi drivers and deregulation as the cause of rows between taxi drivers over everyday fares. Jerry Brennan, from Siptu, described taking another taxi driver's fare as "morally wrong," and he said rows between drivers inevitably caused stress for customers.
"The person in the wrong is the person who took the job but shouldn't have taken the job. Morally it's wrong.
"It causes stress to the public who are half way into the car and the taxi drivers start arguing over who should have the job."
He added that the deregulation of taxis had been the root cause of stress to taxi drivers.
"There are far too many taxis since 2000, and there's been a massive churning out of taxi licences. It's very difficult for taxi drivers to deal with it.
"There are too many licences out there and too many people are trying to compete for too few jobs."