Bylaws covering casual trading that were held up by a court challenge are a threat to hawkers on Limerick's main street and areas around the traditional Milk Market.
A legal opinion is now being sought by the corporation on the validity of the bylaws after they were originally passed by the city council in 1998 under the Casual Trading Act.
Mr Dick Tobin, acting director of services, said they could be introduced within a month depending on the legal advice, making casual trading illegal.
About 50 Saturday traders selling clothes, shoes and brica-brac in the streets around the Milk Market would be affected immediately, as well as people selling periwinkles, posters, jewellery and clothes in O'Connell Street during the week.
"If the bylaws come in in their present form, they will have to stop selling on the street and they will only be able to sell in the vicinity of the market on Saturdays, or seven days a week in particular locations," said Mr Tobin.
"Short-term, everyone trading around that market would have to obtain a licence. At the moment, outside the market, there is no requirement to pay a toll, dues or anything."
The right of the corporation to pass bylaws was unsuccessfully challenged in the High Court and Supreme Court by Mr Michael Bridgman, a trader, and by the Irish Organisation of Market and Street Traders.
Mr Bridgman claimed trading spaces being created at the city's Milk Market could not accommodate his vehicle and that his livelihood was threatened as a result.
The city's chamber of commerce has favoured the removal of traders from the main street for 10 years. Its president, Mr David O'Mahony, who runs a bookshop in O'Connell Street, said casual trading should not be conducted in a haphazard way along the main thoroughfare. The practice was unsafe and an eyesore.
He favours the Milk Market being developed so that it would also operate on a Friday and a Sunday.
"Big chain enterprises" often had branded sports and leisurewear on sale for very low prices. "We have a number of members who would raise serious issues about the goods being traded. Their origin is very suspect," he said.
But a city councillor, Mr John Gilligan (Independent), who has represented street traders in the past, said the adage, "Let the buyer beware", applied to goods being sold in the street.
"People in Limerick appreciate a bit of colour and life in their city. People want more life in the street, not less. Whereas other cities have built on this, we are going in the opposite direction."
With the exception of the Christmas period, street traders were not causing a problem and were earning their livelihood. "What about the traditional periwinkle-sellers who have been in the streets for years? What happens with them?" he asked.
One periwinkle-seller, Ms Ann Keenan, said family members had been selling the seafood and "dillisk" sea grass for 20 years in Limerick, collecting the produce in Lahinch, Co Clare. She said she made about £50 a day.
Cllr Gilligan said the traders and the corporation would have to sit down and decide what was best for the market and for Limerick.
Mr Tobin said he wanted a review of the situation as new issues had arisen since the bylaws were devised, and amendments on traffic regulation would be necessary.
The city was part of an international programme on "Promoting Local Distinctiveness", and open-air markets were part of that distinctiveness.
"We do not want the city to lose its character simply in order to regulate trading. We would very much encourage people to come forward with their ideas and their proposals so we can have a fairly healthy debate on the issue," he said.