Monmouth MP David Davies said Velothon Wales lied when, he claims, it told him MPs backed the event.
About 15,000 cyclists will join in Sunday's race through Newport, Torfaen, Monmouthshire, Cardiff and Caerphilly. Some roads will be shut.
Velothon Wales said its team did "their best" to give "clear information" and "never intended to mislead anyone".
Mr Davies launched the stinging attack during BBC Radio Wales' Jason Mohammad programme on Wednesday.
"The arrogance of this organisation - they're telling lies to people," he said.
"They told me that all MPs support it, and that was a lie, they back-tracked when they found out that I was an MP. They told me they consulted with MPs in April, that was a lie because there was no MPs in April."
Ahead of the general election in April, all MPs became candidates.
On Tuesday, businesses affected by the road closures said they would lose millions of pounds as a result. Residents claimed they will be trapped in their homes on race day.
Mr Davies said businesses that lose money should be compensated.
"Why should they suffer if somebody else is making a lot of money," he said.
"I keep hearing that this (event) is going to generate millions of pounds - I'm not sure how."
In a statement, director of Velothon Wales Andrew Taylor said there had been a long-term "programme of engagement" with residents and businesses about the 140km (87m) race.
"This has included a dedicated team and helpline who are doing their best to provide clear and full information to the people who need it and of course have never intended to mislead anyone," he said.
"The route for Velothon Wales was chosen in consultation with local authorities. We do understand that some of the road closures can cause disruption but unfortunately they are unavoidable and are part and parcel of a closed-road event of this scale."
Mr Taylor went on: "Velothon Wales is a fantastic opportunity for Wales to showcase its iconic landmarks and stunning scenery with a direct impact estimated to be in excess of Â£2m to the Welsh economy."
Organisers of a major bike race have been accused of lying over its consultation for the event.