Lance Armstrong's return to the race he dominated for seven years has created an intense rivalry with team mate and title contender Alberto Contador.
|Contador knows he will have to work hard to avoid an Armstrong challenge [AFP]
Spaniard Contador, who was a winner in 2007, will lead the Astana team but with veterans like Armstrong and Tour podium finishers Levi Leipheimer and Andreas Kloeden in his team, his margin for error is extremely slim.
The Armstrong v Contador rivalry is not unlike that between Bernard Hinault and American Greg LeMond, who won the 1986 race despite repeated attacks from his French team mate.
Although Astana manager Johan Bruyneel has made it clear Contador is the leader and Armstrong his lieutenant, the seven-times champion is likely to try his luck early in the race to turn the hierarchy upside down.
"I would love to be a little mouse and see how it goes within Astana," Tour director Christian Prudhomme said.
"Contador will have only a week, and actually two stages, to show he is the boss in his own team."
The opening 15.5-km time trial in Monaco on Saturday should give an indication of the favourites' form on a course tailor-made for climber Contador with its 7.5-km ascent to the Cote de Beausoleil in the first part.
Contador, one of only five riders with victories in all three Grand Tours, is also expected to make a move in the seventh stage which finishes with an out-of-category climb to Arcalis.
Should he still be in contention at that time, Armstrong, back on the bike after 3 1/2 years in retirement, is convinced he can cause an upset.
"I feel strong, I feel strong enough to win," he told French radio Europe 1.
"It will be close. Three to one."
But Contador has shown he has no rival when the slopes get really steep and he has dramatically improved against the clock as he proved by winning the Spanish time trial title last week.
The ascent in the penultimate stage to the Mont Ventoux, where Armstrong has often struggled, will be his last master card.
"I'm a much stronger rider all round," the 26-year-old said
Contador will also have rivals outside his team.
There is Silence-Lotto's Australian Cadel Evans, runner-up the past two years, although the main threat is likely to come from Saxo Bank and the Schleck brothers, Andy and Frank, who have a very strong team at their disposal.
Champion Carlos Sastre, who left Saxo Bank for Cervelo, cannot be counted out, having shown great form in the Giro, where he snatched two mountain stages.
Giro champion Denis Menchov of Russia will be another contender although Marco Pantani in 1998 was the last man to clinch a Giro/Tour double.
Contador, however, will not have to deal with compatriot Alejandro Valverde, who has been left out of the Caisse d'Epargne team over his alleged involvement in a blood doping scandal in 2006.
Anti-doping authorities have warned they will be merciless after the last three Tour editions were tainted by drugs scandals.
"The Tour de France will be the most tested event in the history of sports," said International Cycling Union (UCI) Pat McQuaid.
The UCI and the French Anti-Doping Agency (AFLD) will work together to carry out more than 500 tests throughout the race.
Fifty of the 180 riders will be tested more because they are either top contenders or their biological passport data has raised suspicions in the UCI, McQuaid said earlier this month.