The local authority wants to carry out essential work on the water mains on the town’s Muckross Road.
The road boasts a large number of hotels and B&Bs.
The council plans to close one traffic lane on the road.
The route on the Ring of Kerry, is known locally as the golden mile, leading to Killarney National Park and Kenmare.
Tourism interests yesterday claimed September is a busy month in Killarney and said nothing should be done to disrupt traffic.
Killarney tourism officer, Michael Courtney, called for the pipe-laying work to be postponed until later in the year.
“September and October are generally very good months for tourism here,” he said.
Town Councillor Brian O’Leary said it would be outrageous to close the road at that time.
“This is a scandalous proposal which has been poorly thought out. No other organisation would come up with a suggestion like this. Part of the plan is to divert traffic to roads where there’s a tonnage restriction in place. It would be a recipe for chaos in September when traffic in the town would be chock-a-block.”
Town council manager, John Breen, said the work was necessary and other agencies were involved.
He would have to take the views of such agencies on board and would come back to the council on the matter.
“The work must be done and we’ll push it out as far as we can,” he said.
Water mains are being replaced from the Ross Road junction to Flesk Bridge, while sewer and storm water pipes are being extended.
The plan is to start the work on September 15, with traffic diversions via Countess Road, Rookery Road and Woodlawn Road.