UCI president Pat McQuaid on Tuesday called on ProTour riders to pledge their commitment to a dope-free Tour de France by making a sample of their DNA available and lodging the equivalent of a year's salary, which they will lose if they fail a drugs test in next month's race.

Doping cases have rocked recent editions of the world's premier cycling race. Last year's winner, American Floyd Landis, stands accused of using performance-enhancing substances on his way to victory.
FullText of Riders' Pledge

Speaking during a press conference after a meeting between the UCI and the 20 ProTour teams, McQuaid presented a letter that he invited all 600 ProTour cyclists to sign before the Tour starts in London on July 7.

"I accept that if I break the UCI's anti-doping regulations to pay in addition to the statutory sanctions a contribution equal to my salary for 2007," read the letter, which was signed on the spot by France's Sandy Casar (Française des Jeux) and Britain's Mark Cavendish (T-Mobile).

"At the same time I declare to Spanish authorities that my DNA is available to be compared with the blood bags seized as part of the Puerto affair," the letter continued.

Spain’s Operación Puerto has lingered for more than a year after the offices of Madrid gynecologist Eufemiano Fuentes were raided in May of 2006. Police seized nearly 200 bags of blood, an assortment of doping products and a coded logbook suggesting an elaborate and organized doping program.

Former Tour winner Jan Ullrich and 2006 Giro d’Italia winner Ivan Basso were among several riders barred from last year’s race.

While McQuaid insisted that the pre-Tour letter was not a requirement, it would be "up to the teams to decide what to do with” riders who decline to sign.

Anne Gripper, head of the UCI's anti-doping program, believes that any rider who refuses to sign it would probably not start the Tour de France "not for legal reasons but because of the pressure."

Tour de France chief Christian Prudhomme told AFP that organizers will refuse entry to any rider or teams failing to sign the anti-doping pledge.

"We will block their entry to the race," Prudhomme told AFP, adding that the UCI's "positive" measure came in the wake of a letter he sent to all participating teams last week.

According to Prudhomme, three teams - T-Mobile, Rabobank, and Agritubel - have already responded.