Seven-time Tour de France champion Lance Armstrong said he would no longer fight doping charges by the U.S. Anti-Doping Agency, which quickly said it would strip him of his titles and ban him from competitive cycling.
Armstrong, a cancer survivor considered one of the all-time greats in his sport, made the announcement in a written statement as he faced a midnight deadline on Thursday to formally challenge the accusations against him.
"There comes a point in every man's life when he has to say, 'Enough is enough'," the American cyclist said in the statement, which was posted on his website, Lancearmstrong.com.
"For me, that time is now. I have been dealing with claims that I cheated and had an unfair advantage in winning my seven Tours since 1999."
A short time later a spokeswoman for the USADA, Annie Skinner, said the agency would strip Armstrong of his seven Tour de France titles and ban him from the sport of professional cycling for life.
"It is a sad day for all of us who love sport and our athletic heroes," Travis Tygart, USADA's chief executive officer, said in a statement released to Reuters by the agency.
"This is a heartbreaking example of how the win-at-all-costs culture of sport, if left unchecked, will overtake fair, safe and honest competition, but for clean athletes, it is a reassuring reminder that there is hope for future generations to compete on a level playing field without the use of performance-enhancing drugs," he said.
"I WILL TURN THE PAGE"
If the USADA takes away Armstrong's titles he would become one of the highest-profile athletes to face such a sanction, at least since Canadian sprinter Ben Johnson was disqualified from the 1988 Seoul Olympics after winning a gold medal in the 100 meters.
Texas-born Armstrong, who retired from professional cycling last year but remains the face of his anti-cancer charity, Livestrong, has long denied that he used performance enhancing drugs to help fuel his career.
He maintained that emphatic denial in the statement issued on Thursday, stressing that there was no physical evidence to support what he called Tygart's "outlandish and heinous claims".
Armstrong, who never failed a doping test, said he would "jump at the chance" to put the allegations to rest once and for all, but refused to participate in the USADA process, which he called "one-sided and unfair".
"Today I will turn the page," Armstrong said. "I will no longer address this issue regardless of the circumstances."
He disputed the agency's authority to take away his titles.
Johan Bruyneel, the former sporting director of the two teams Armstrong won his Tour titles with, is also accused of involvement in the case by USADA and criticized the process while defending the American.
"I'm disappointed for Lance and for cycling in general that things have reached a stage where Lance feels that he has had enough and is no longer willing to participate in USADA's campaign against him," the Belgian wrote on his blog www.johanbruyneel.com.
"Lance has never withdrawn from a fair fight in his life so his decision today underlines what an unjust process this has been."
World Anti-doping Agency (WADA) chief John Fahey said that Armstrong's decision not to contest the allegations should lead to the American being stripped of his Tour de France wins.
"He had the right to rip up those charges but he elected not, therefore the only interpretation in these circumstances is that there was substance in those charges," Fahey told Reuters in a telephone interview on Friday.
"My understanding is that when the evidence is based upon a career that included seven Tour de France wins then all of that becomes obliterated."
A spokesman for the International Cycling Union said it would put out a statement later on Friday.
It was not immediately clear if Armstrong's bronze medal at the 2000 Sydney Olympics was in jeopardy.
Armstrong, 40, has been one of the most successful and controversial cyclists of all time, returning to the sport after beating cancer to win the Tour de France an unprecedented seven times in succession from 1999 to 2005.
Livestrong, known for its popular yellow bracelets, takes its inspiration from his achievements and recovery from testicular cancer that also made him a hero to many Americans and boosted the sport's popularity in the United States.
The USADA, a quasi-governmental agency created by the U.S. Congress in 2000, formally charged Armstrong in June with doping and taking part in a conspiracy with members of his championship teams. Five other cyclists have been accused of conspiring with Armstrong over the course of 14 years to hide doping activity.
The agency said in a letter to Armstrong that it has blood samples from 2009 and 2010 that are "fully consistent" with doping.
In the letter, which was published in the Washington Post, the agency said it also has at least 10 former teammates and colleagues of Armstrong who will testify he used doping drugs during races from 1999 to 2005.
Former teammate and deposed Tour de France winner Floyd Landis accused Armstrong in 2010 of using performance-enhancing drugs and teaching others how to avoid being caught.
Landis said he witnessed some of his teammates, including Armstrong, use illegal drugs to boost performance and endurance.
On Monday a federal judge dismissed Armstrong's effort to block the probe, despite a contention by his lawyers that USADA gathered evidence by threatening to ruin the careers of fellow cyclists who have agreed to testify against him.
His attorneys also argued that the agency's rules violate his right to a fair trial and that it lacks proper jurisdiction to charge him.
But Armstrong could have carried on his fight against the USADA allegations through the agency's arbitration process, contesting the evidence against him at a hearing.
In February, the U.S. Justice Department dropped an investigation centered on whether Armstrong and his teammates cheated the sponsor of their bike racing team, the U.S. Postal Service, with a secret doping program.