Chris Froome has suffered fractures to his femur, elbow and ribs after crashing in the Criterium du Dauphine on Wednesday.
Six-time Grand Tour champion Froome crashed towards the end of a route recon in Auvergne-Rhone-Alpes, sustaining multiple serious injuries.
He was immediately taken to Roanne Hosptial for assessment and stabilisation, and Team INEOS principal Dave Brailsford confirmed the 34-year-old would miss the Tour de France.
The extent of Froome's injuries have now been disclosed, with Team INEOS doctor Richard Usher revealing the 34-year-old was being airlifted to St Etienne University Hospital for further treatment.
"Our primary focus now is obviously on ensuring Chris gets the very best possible care, which he will do, so he can recover as soon as possible," Brailsford said in a Team INEOS statement.
"One of our big strengths on this team is coming together in difficult moments, and we will ensure we do everything possible to support Chris and his family.
"Even though we all recognise the risks involved in our sport, it's always traumatic when a rider crashes and sustains serious injuries.
"Chris had worked incredibly hard to get in fantastic shape and was on track for the Tour, which unfortunately he will now miss.
"One of the things which sets Chris apart is his mental strength and resilience – and we will support him totally in his recovery, help him to recalibrate and assist him in pursuing his future goals and ambitions."
Froome, a four-time Tour de France winner, had been set to lead Team INEOS in the event, which begins in Brussels on July 6.
The last of his four titles came in 2017, with team-mate Geraint Thomas having claimed the yellow jersey in 2018.