Fait Accompli, which organises functions and garden parties in Buckingham Palace, is believed to have secured the catering at the tournament on July 5-6.
The social highlight of the event is a gala banquet held in a huge marquee.
Fait Accompli would not comment when asked if they had been hired.
But city mayor Kevin Kiely said: “I attended the last banquet five years ago and all the catering by Irish staff was done very professionally.
“Under the current economic situation many chefs, waiters, waitresses and others who worked in the catering industry are out of work and would appreciate any work they can get at the JP golf dinner.
“I would appeal to the company with the contract to hire Irish staff who are out of work and who are world class at their job.”
More than 1,000 guests are expected to attend the golf classic banquet. Industry sources said the event would give up to four days work for about 150 catering workers.
Celebrity guests who have accepted invitations to take part in the tournamentinclude actors Hugh Grant and Kyle MacLachlan.
Fait Accompli, one of whose principals, Camilla Monckton, is a close friend of members of the royal family, did the catering at the lavish wedding in July 2007 of JP McManus’s daughter, Sue Ann, to Kerryman CianFoley.
More than 1,500 guests attended the wedding reception in a vast marque which was erected in the grounds of Martinstown Stud.
Cian and Sue Ann recently moved into Islanmore Stud in Croom
Fait Accompli engaged scores of Irish chefs and other catering personnel for the Martinstown wedding but there is some speculation in the catering industry the London firm may bring their entire catering team to Adare for the golf event.