The International Cycling Union (UCI) has issued a cautious response to the US Anti-Doping Agency (USADA) announcement, which Armstrong, 40, has denounced as being part of a “witch hunt” against him.
The UCI has contended it should have jurisdiction over Armstrong’s case as it was responsible for carrying out doping tests while he competed. The American has been at pains to point out he has never failed a test.
The UCI could choose to appeal to the Court of Arbitration for Sport in Switzerland against the USADA ruling, or to gain jurisdiction over the case.
The decision by Armstrong - one of sport’s greatest serial champions - to stop fighting doping allegations means his record will be forever tarnished as that of a cheat.
Yet the Texan continues to deny any wrong-doing, claiming: “There comes a point in every man’s life when he has to say, ‘enough is enough’. 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.”
Armstrong was known as a ferocious rider who never quit, and won worldwide admiration for his battle against cancer, returning to health to win cycling’s most famous race seven times.
While his sporting record will be destroyed, his heroic standing outside cycling will surely also be tarnished.
Armstrong’s Livestrong foundation, which helps cancer survivors, helped start the trend of charity wristbands, and his yellow bracelets became trendy for celebrities and fans alike in the middle of the last decade, raising millions of pounds.
On Twitter, Lord Sugar reacted to the news the cyclist was giving in by saying: “Lance Armstrong says can’t be bothered to fight over drug allegations. Yeh right ... you would fight like crazy to retain your integrity.”
Rugby’s Mike Tindall said: “The biggest loser in the Lance Armstrong affair is the sport of cycling, to try and change results over the 15 years seems ridiculous.”
But others defended Armstrong, saying he never failed a drugs test.
Armstrong chose to back down from fighting an investigation by USADA into allegations that he cheated by using banned substances.
The International Cycling Union (UCI), the sport’s governing body, had backed the retired rider’s legal challenge to the agency’s authority to act.
USADA chief executive Travis Tygart said the UCI now had “no choice but to strip the titles under the code”.
He said: “It is a sad day for all of us who love sport and athletes. It’s a heartbreaking example of win-at-all-costs overtaking the fair and safe option. There’s no success in cheating to win.”
The USADA has said previously that 10 of Armstrong’s former team-mates were ready to give evidence against him, alleging he used banned substances as far back as 1996.
Known to cycling aficionados, Armstrong came to transcend his sport after writing It’s Not About The Bike, the inspirational story of his fight to survive testicular cancer in 1996 and go on to win his first Tour de France three years later.
His love life also saw him featuring in the gossip columns after he divorced his wife and mother of three of his children Kristin Richard, got engaged to singer Sheryl Crow, only to split with her and father two more children with girlfriend Anna Hansen.
He has also dated actress Kate Hudson in the past.
Armstrong was named BBC Overseas Sports Personality of the Year in 2003. The BBC will not remove that title from him following his announcement.
A BBC spokeswoman said: “Lance Armstrong was voted Overseas Sports Personality of the Year based on his sporting achievements at that time.”
As news broke Armstrong is to be stripped of his titles, French cycling veterans lamented the stain on the world’s most famous bike race, but the newspapers felt justice was finally being done and online commentators asked whether France might now see more of its cyclists on the podium.
“Armstrong personified impunity. He was seen as too well protected to fall. So the big message today is that impunity is over,” said Damien Ressiot, a sports reporter who published the first doping allegations against Armstrong in the sporting daily L’Equipe seven years ago to the day.
“What is a shame is that by saying he accepts the decision, Armstrong will avoid a public debate so we’ll never know exactly what happened and how he was able to cheat for so long.”
Beating testicular cancer to win the Tour an unprecedented seven times, Armstrong, clad in the leader’s yellow jersey, came to close to personifying the race from 1999 until his retirement last year, popularising it with millions of Americans.
He also became an inspiration for cancer sufferers worldwide.
While the American, who speaks basic French, was always publicly cheered in the country that made him one of cycling’s greats, many people regarded him as standing for a generation of cheats who always seemed to get away with it.
“The rotten years of cycling have been identified and Lance Armstrong is out,” Jean-Rene Bernaudeau, head of French cycle racing team Europcar, told Reuters. “We are working as hard as we did then and we have better results. French cycling has regained its standing.”
Veteran French racing cyclist Laurent Jalabert, widely popular in France though he never won the Tour, told RTL radio he felt sadness and anger at the blight on both the Tour de France and the wider world of professional cycling.
“The axe has fallen,” wrote daily newspaper Le Figaro in its online edition. “Some people will be furious but others will see justice being done.”
Le Monde said Armstrong’s downfall should serve as a turning point for the sport. “Saint Armstrong, pierced with arrows, has finally succumbed,” the newspaper said in an editorial. “This illustrates anew that this sport is poisoned by doping.”
Many in France are angry at the way doping has come to overshadow the glory of a punishing three-week race that courses 3,500 km (2,200 miles) through the mountains and valleys of France at breakneck speed and has been held every year, except in wartime, since 1903.
While French cyclists have over the years been most successful in the event, winning 36 of the 94 tours, the last Frenchman to win was Bernard Hinault back in 1985.
Since then, American and Spanish riders have dominated, with Armstrong and Spaniard Miguel Indurain recording seven and five wins each. This year’s Tour was won for the first time by a Briton, Olympic gold-medallist Bradley Wiggins.
“That’s it - we are going to have a Frenchman back on the podium,” one online reader of L’Equipe commented in reaction to the Armstrong story.
“At last!” said another. “Everyone knew (Armstrong) was guilty - he was the only one able to talk without panting when he got to the top of a hill.”
The USADA has based its case on eyewitness accounts that Armstrong, along with other leading Tour de France cyclists, were injecting themselves with the blood booster EPO, testosterone and other performance-enhancing drugs.
While Armstrong is only one among several Tour de France champions accused of doping, he is by far the most prominent.
Bernard Thevenet, who won the Tour de France twice, said stripping Armstrong of the titles that have made his fortune and turned him into a global brand would send a clear message that things have changed.
“If Armstrong cheated then it’s perfectly reasonable that he should be punished,” he told RTL radio. “It’s a very strong message for cyclists and those around them who might be tempted to cheat.”
Ressiot, for whom Armstrong’s fall feels like vindication for his years-long quest to get recognition for his claims that urine samples from Armstrong in 1999 had tested positive for EPO, said the best outcome would be to set up a much more stringent testing system.
“Of course this hurts the Tour’s image, but the stain from doping affairs of the last 15 years was already catastrophic so I don’t think anyone is surprised. The problem today is that all great sporting results are viewed with suspicion,” Ressiot said.
“I am saddest for the cancer sufferers who made Armstrong a hero. He biggest crime was to lie to those people,” he said.