Andy Schleck is gambling on being able to overthrow Tour de France 2010 leader and defending champion Alberto Contador on the Spaniard's favourite terrain when the race reaches the Col du Tourmalet on Thursday.

Tour organisers designed this year's route in the hope the race would be decided on the 18.6-km climb to the Tourmalet at an average gradient of 7.5 percent.

Their wish appears to have been fulfilled as Luxembourg's Schleck, runner-up to Contador last year, is trailing the Astana rider by only eight seconds.

Contador, who earlier this year told Reuters the Tourmalet was his favourite climb, took the leader's yellow jersey off Schleck on Monday when the Saxo Bank rider suffered a problem with his bike chain on the final ascent of the 15th stage.

"I will take my revenge," Schleck said at the time, however he shook hands with Contador on Tuesday.

Schleck is considered a match for Contador in the mountains but a weaker time trialist. As a result, there have been countless calculations and discussions in the peloton about the gap Schleck would need over his rival ahead of Saturday's final 52-km time trial to stand a chance of overall victory.

The pair have mentioned 90 seconds as the probable difference between them in the last timed effort, although Schleck cut his estimate to one minute on Wednesday.

"Since the start of the Tour de France, his team mates did a great job in protecting Alberto. They all know how important is tomorrow's stage," Astana manager Yvon Sanquer told Reuters.

"In this stage, we are waiting for Schleck's attack. He made it very clear he would be aggressive."

Both riders marked each other in the first stage in the Pyrenees last Sunday, allowing Samuel Sanchez, third overall, and fourth-placed Denis Menchov, to speed past them in the final climb.

"If they play this little game again tomorrow, we could have someone like Menchov taking advantage of the situation and winning the Tour," Garmin-Transitions manager Jonathan Vaughters told Reuters.

The scenario is unlikely, though, as Schleck is expected to attack from the bottom of the climb, just after the Pyrenean town of Luz St Sauveur when the menacing figure of the Tourmalet appears.

The prospect does not scare the bold Schleck.

"I am in the form of my life," he told reporters in a packed media conference at his Saxo Bank team hotel on Wednesday.

"I am ready to risk my second place to win the Tour."