MADRID (REUTERS) - Chris Froome's hopes of pulling off a rare Tour de France-Vuelta double are over after he was forced to withdraw before Thursday's 12th stage after a heavy crash on Wednesday left him with a fractured bone in his foot.

The twice Tour de France winner and Team Sky leader went down at the start of the brutally mountainous 11th stage in the Pyrenees and eventually limped across the line more than seven minutes behind new leader Fabio Aru of Astana.

"Scans this morning confirm fractured navicular," Froome wrote on his Twitter feed. "End of the Vuelta for me."

The British cyclist appeared close to pulling out when he was dropped from the group of main contenders with three of the six climbs remaining in the punishing Queen stage, billed as one of the toughest ever set in a grand tour.

But the 30-year-old, who said he was knocked sideways into a barrier and wall in the crash, doggedly continued with the help of his team-mates and managed to finish.

However, after losing so much time, and with 10 stages remaining, Froome's hopes of emulating Frenchmen Jacques Anquetil (1963) and Bernard Hinault (1978) as the only men to win the Tour and Vuelta in the same year were clearly over.