Stuart Davies has made his demand after discovering that police have prosecuted just one motorist in the past five years for breaking the existing 60mph restriction on the A542 route from Llangollen towards Llandegla and Ruthin.
Cllr Davies said: “I recently put in a Freedom of Information request to North Wales Police which reveals that since 2009 they have brought only one prosecution for speeding on the Horseshoe Pass and this was in the financial year 2013/14.
“If they aren’t prosecuting people for breaking the 60mph limit up there why do they want to lower it to 40mph?
“It doesn’t make sense to me, especially at a time when Denbighshire County Council is being asked to make deep cuts in its budget of around £30 million over the next few years affecting essential services.
“I am told that implementing the new 40mph restriction, with the cost of consultation and new signs, would be £20,000 and I’d argue we just can’t afford that sum when it appears that people aren’t being prosecuted for breaching the limit that’s already in force.”
He added: “I know that some work has already gone into it but my view is that any further work on it should be stopped immediately.”
Official figures show that over the past five years the Horseshoe Pass has been the scene of 22 collisions involving slight injuries, 10 rated as serious and two which were fatal.
North Wales Police traffic officers recently requested the county council to impose a 40mph limit on the whole of the pass from the Britannia to the cattle grid at Pentre Isaf.
When he first raised the issue a few months ago, Cllr Davies said: “I am of the view that better enforcement of our existing laws and better education of drivers at the hotspots would slow down traffic and safeguard lives rather than the blunt use of a blanket speed limit over the whole of the pass.”