Former Tour de France winner Bjarne Riis has thrown the gauntlet down to his team’s rivals for the race’s yellow jersey, declaring that his Saxo Bank outfit will be hard to beat.

Riis, the 1996 Tour winner who two years ago admitted to having used the banned blood booster EPO as a rider, won the race for the first time as manager last year when Spaniard Carlos Sastre triumphed for CSC.

Now with a new sponsor, Saxo Bank, Riis believes that despite Sastre’s move to the Cervelo team they have the tools to beat their biggest rivals here – the Astana team spearheaded by Alberto Contador and Lance Armstrong.

Contador, 26, is the 2007 yellow jersey champion while 37-year-old Armstrong’s record seven Tour triumphs means he, despite a four-year absence, remains a strong contender.

Add experienced American Levi Leipheimer and German Andreas Kloden, who has twice finished on the race podium, and Astana’s yellow jersey options over the July 4-26 race multiply.

Uncertainty has surrounded whether Astana will give all their backing to Contador, who has reportedly been vexed by Armstrong’s arrival last year.

While Riis’s plan is to start with Andy Schleck as team leader and his older brother Frank as back-up, he believes Astana will kill off any remaining doubts about who their team leader is by forcing Armstrong into supporting Contador.

“To me, it’s obvious they should have one leader and to me, that leader is Contador,” Riis said Thursday, two days before his team, and Fabian Cancellara in particular, aim to grab the first yellow jersey of the race.

“If I should take a guess, that’s the way it is going to be. If they have other plans, then it’s going to be funny to watch.”

Riis admits Astana will be one of the teams to beat, but he hinted that Armstrong age – and his long absence from the sport – could leave him struggling against “younger kids” in the crucial mountains stages.

“Lance is not too old (to compete) – maybe to win, but we’ll have to wait and see,” added Riis.

“But to be honest, to beat these young kids today, like Andy and Frank, I just don’t believe it – although he (Armstrong) will have an important role to play.”

Armstrong, who won the Tour from 1999 to 2005, returned to competition in January after three years out of the sport and has since competed in the three-week Tour of Italy where he finished an impressive 12th place overall.

Veteran Stuart O’Grady, back for his 13th Tour campaign following yet another recovery from serious injury, believes the American still has plenty to offer but would find it extremely difficult to win.

“The Giro was pretty pivotal, it was a big test for him and he (Armstrong) passed with flying colours. And I can imagine that Lance has been training the house down since,” said O’Grady.

“He definitely comes across as though he’s still got the focus and the energy. It’s going to be extremely difficult for him, but Lance has won seven Tours before so if anyone can do it then Lance can do it.”

Riis warned, however, that whoever Astana choose to lead their charge towards the yellow jersey better be prepared for a fight.

“We have trained and raced hard to be in the best possible condition for this Tour,” he added.

“We’re ready for some big results, no doubt about that. Although Carlos is no longer here, we’re ready to defend our yellow jersey.”