AIGLE, Switzerland — The head of cycling’s world governing body believes it will take more than one scandal-free Tour de France to convince the public that cycling has beaten its doping problems.

“This year’s Tour probably will go down as one of the cleanest on record,” International Cycling Union president Pat McQuaid told The Associated Press in the lead-up to Saturday’s start of the three-week race. “But I don’t think one clean Tour de France is going to change the image and the perception of cycling in a lot of people’s minds. It’s going to take some time but it’s certainly a big step on the way.”

McQuaid praised tour owner Amaury Sports Organization for taking a tough line on whom it has allowed to enter after doping scandals dominated the past two Tours.

The Astana team was excluded as punishment for past problems, despite being under new management and signing 2007 Tour winner Alberto Contador last winter. Belgian sprint specialist Tom Boonen has also been banished after testing positive for cocaine in an out-of-competition control.

“There is a genuine effort being made by everyone involved that it will be a clean Tour,” McQuaid said. “They (ASO) are terrific organizers, the best in the world, make no mistake about it. They have been doing it for a long time.”

It was a rare accolade from McQuaid, whose organization is involved in a feud with ASO about who is to blame for past doping problems and the future of cycling.

ASO decided to ignore UCI rules and stage this year’s Tour — and the Paris-Nice race in March — under the authority of the French national federation and anti-doping agency instead. UCI responded by suspending the French federation.

“For the first time ever the Tour de France is not on the UCI calendar and it saddens me, there’s no doubt about it,” said McQuaid, who has not been invited to attend.

It will be the first Tour he has missed since working for Irish state broadcaster RTE 25 years ago, at the start of a golden era for his compatriots Sean Kelly and Stephen Roche, who won the Tour in 1987.

McQuaid will be far from France in the first two Tour weeks, preparing for the Olympic cycling program in Beijing and attending the world junior championships in South Africa. He will return to his Swiss home before the race reaches Paris on July 27.

“Under the current circumstances I don’t think I could accept an invitation from ASO,” he said. “Not just to sit and watch the race. If there was a possibility that it would lead to a calming of the situation and discussions — I don’t say negotiations — then I would, of course.”

The two sides have not shared a public platform since last October, at a launch of the biological passport scheme for riders designed to clean up the sport and restore the confidence of fans and sponsors.

The UCI has steered the $8.2 million project in which more than 850 riders have given a series of blood and urine samples while in training and during races to set the parameters for an individual biological profile.

Laboratory teams can then identify doping offenses from abnormal test results rather than seeking and identifying each prohibited substance.

“It has given the message to these guys that it’s over,” McQuaid said. “There is no point in trying to start fiddling with blood nowadays because you’ll be caught.”

McQuaid said the UCI has acted quietly and effectively on suspicious results without naming offenders in public during the trial stages.

“We’ve seen information on a couple of riders — it’s only a couple — and we’ve discussed with the rider and the team the information we’ve seen and decisions have been taken.

“The UCI is 100 percent committed to cleaning the sport and having doping-free cycling and ASO need to recognize that. They may do at the end of the Tour.”