Jonathan & Charlotte have been forced to pull out of a performance before the Queen after singer Jonathan Antoine was again diagnosed with acute depression.
The teenage pair were due to take part in the Royal British Legion Festival of Remembrance event at the Royal Albert Hall on Saturday.
But as a result of his illness, Jonathan has been told to drop all engagements for at least a month and the Britain's Got Talent stars have had to withdraw.
The duo - who have scored two top five albums - offered their apologies to the Queen, the Royal British Legion, members of the armed forces and ticket-holders for their cancellation.
Jonathan, 18, has previously spoken about problems with his mental health which led to him self-harming and considering taking his own life before he found fame on BGT. He has said it was related to chronic insomnia.
"I felt that life was pointless. I was suicidal," he said in an interview last year. "My life just felt pointless. The whole thing. I felt like I was going to be at school forever and just die there."
A statement issued on Jonathan & Charlotte's behalf said they were pulling out of the Remembrance show.
It said: "The pair made this decision after Jonathan was diagnosed once more with acute depression. As a result, he has been advised by doctors to cancel all work commitments for at least one month.
"Jonathan's previous battles with depression have been well-documented. Jonathan, Charlotte and their families request the media allow them the appropriate privacy - and Jonathan the time and space to make a complete recovery - at this difficult time."
