Contador left his previous team after they failed to get a sponsor

Contador agreed to join Astana on a two-year deal at the end of 2007 when the Discovery Channel team disbanded.

But Astana's history of doping scandals has resulted in their exclusion.

"My aim this year was to win it again, but they've deprived me of that opportunity. Astana should be in the Tour," said the Spaniard.

Astana's assistant sporting director Sean Yates predicted Contador would stay with the team.

"Alberto has faith in his team, he has faith in manager Johan Bruyneel and will be out to win the Tour of Spain and then next year's Tour," Yates told BBC Radio 5 Live. "He's still very young."

Astana took over from Liberty Seguros, a team that was left out of the 2006 Tour after several of their riders were barred from taking part in the race because of their alleged implication in the doping investigation named Operation Puerto.

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But then the team was forced out of last year's race after Alexandre Vinokourov tested positive for blood doping and was sacked.

Former Astana team members Andrey Kashechkin and Matthias Kessler also lost their places after failing doping tests.

"We remember what happened in 2006," said Tour de France race director Christian Prudhomme.

"Then came 2007 with a new team who asked us to trust them. We did that and paid dearly for it."

Events at the 2007 Tour also led to the team's exclusion from the 2007 Tour of Spain.

In an effort to improve their reputation, they appointed Johan Bruyneel, who managed Lance Armstrong to seven straight Tour titles from 1999-2005, as general manager as well as bringing in other new faces.

But the new recruits failed to prevent them from being barred from the 2008 Giro d'Italia and, now the Tour de France and other events organised by Amaury Sport Organisation.

Despite last year's ban from the Tour of Spain, however, race organisers have decided to allow them to take part this year.

"The Vuelta excluded Astana last year when they didn't deserve our confidence, but that confidence has been renewed and teams that don't have any problems with doping will be invited," said race director Victor Cordero.