Tour de France organisers will refuse to let Chris Froome race in this year's event if his salbutamol case has not been resolved, Press Association Sport understands.
The four-time Tour champion returned an adverse finding for the asthma drug during his winning ride at last year's Vuelta a Espana.
The British cyclist denies any wrongdoing and is continuing to race this season, as is his right under the World Anti-Doping Agency's rules, while his team of lawyers and scientists work on an explanation for the adverse sample, which contained twice the allowed concentration of the drug.
The Team Sky rider confirmed on Wednesday his final warm-up race for his first big target of the season, the Giro d'Italia, will be the Tour of the Alps, a five-day race in Austria and Italy that starts on April 16.
The Giro d'Italia's organisers have already said they are powerless to stop the 32-year-old riding in their race and new International Cycling Union (UCI) president David Lappartient has confirmed Froome's case will not be heard before the race starts on May 4.
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But two senior cycling sources have told Press Association Sport that ASO, the French company that runs the Tour, has more discretion on who it registers for its event and has no intention of letting a rider with a potential anti-doping violation hanging over them to race.
ASO is understood to be confident it could resist any legal challenge from Team Sky because its rules have clauses about safeguarding the image of the race.
According to its rules, the UCI could also suspend Froome but Lappartient said it didn't want to do that.
