Bradley Wiggins' Tour de France hopes received a major boost yesterday when Andy Schleck, one of his main rivals, was forced to pull out of the race with a fractured vertebrae.

The 2010 champion, who suffered the injury to his sacrum in a crash during the fourth stage time trial in the Criterium du Dauphine on June 7, described his withdrawal as the "most painful" experience of his career.

The 27-year-old, a three-time Tour podium finisher, underwent an MRI scan yesterday which revealed the extent of the injury, which will rule him out for four to six weeks.

The 2012 edition gets under way on June 30 in Liege, with Britain's Wiggins one of the favourites following his second successive Dauphine triumph.

"This is the biggest disappointment in my life," Luxembourg rider Schleck told a news conference.

"The Tour is the most important race. I feel sad for my dedicated team-mates. I would have been ready to perform. I wanted to give an answer to my critics.

"As a bike rider you never stop believing in goals, in dreams. That's why I also continued on the bike after my crash. I wanted to go on as I had the Tour in my head. I was always thinking that it would become better.

"Riders are hard. I remember Cadel Evans finishing the Tour once with broken ribs, but in the end I really had to quit the race. In my career I've broken my collar bone twice, but this is the most painful thing I've ever had so far."

The Team RadioShack-Nissan-Trek rider battled through to the finish of the time trial, but withdrew from the Dauphine after 63 kilometres of the following day's stage.

Team manager Johan Bruyneel said: "Andy suffered a lot, but put the pain aside. He knew he had to go through the Dauphine to be ready for the Tour de France.

"The fact that he went on for two stages really showed that he was determined to be as good as possible at the start of the Tour. Andy was supposed to be our designated leader for the Tour de France. This is a big blow for the morale of the entire team."

Schleck's withdrawal comes just a month after he was presented with the Tour's symbolic yellow jersey in his home town of Mondorf-les-Bains. Schleck finished second behind Alberto Contador in 2010, but the Spaniard later tested positive for the banned substance clenbuterol and was stripped of the title in February.

And Schleck is looking forward to taking on Contador on his home soil at the Vuelta a Espana in August.

"I will find there my friend Alberto Contador," he said. "It's going to be a nice race there. I am more motivated than ever before.

"After all my bad luck of this year I will come back stronger. I am 27 years old. I still have a lot of years in front of me. You haven't heard the last of me yet."