Florence Welch has cancelled a pair of festival gigs to avoid permanently damaging her voice, as she heads for her first number one single.
The chart singer - who records as Florence + The Machine - said she had suffered a "vocal injury" and has lost her voice after she felt something "snap".
She apologised to fans for the cancellation of the shows in Spain and Portugal.
The redheaded star said: "I've sustained a vocal injury and been told I cannot sing for a week - seriously I felt something snap, it was very frightening.
"Unfortunately this means I will not be able to perform at Benicassim and Optimus Alive festival this weekend.
"I'm so sorry to all the fans, I was desperate to still perform, but was told without question not to, so as not to do permanent damage."
Her vocal problem comes less than a year after fellow chart star Adele was forced to cancel a number of shows and then had to undergo surgery after a vocal cord haemorrhage.
Florence is in line to top the singles chart with Spectrum (Call My Name) on Sunday according to midweek figures from the Official Charts Company.