Former Formula 1 driver Alex Zanardi is having surgery on a head injury after an accident during a handbike relay in his native Italy.
The 53-year-old was involved in a crash with a lorry in Pienza on Friday.
He was taken by helicopter to Siena’s Le Scotte, where the hospital said he was in a “very serious” condition and “undergoing a delicate neurosurgery”.
Zanardi had both legs amputated after crashing in the American Memorial 500 Cart race at Lausitz, Germany, in 2001.
He has since become a four-time Paralympic handcycling gold medallist.
“You have never given up and with your extraordinary fortitude you have overcome a thousand difficulties,” said Italian prime minister Giuseppe Conte on Twitter.
“Come on Alex Zanardi, don’t give up. All of Italy is fighting with you.”
Former world Formula One champion Mario Andretti tweeted: “I am so anxious and frightened about Alex Zanardi that I’m holding my breath. I am his fan. I am his friend.
“Please do what I’m doing and pray, pray for for this wonderful man.”
Zanardi was taking part in an event called the Obiettivo Tricolore, a journey that sees the participants riding across Italy on handbikes, cycles or wheelchairs.