-One Direction star Zain Malik also forced to pull out for 'personal reasons'
Concerns: X Factor semi-finalist Matt Cardle was unable to perform at a secret gig put on by the show's sponsor Talktalk last night because he had lost his voice
X Factor favourite Matt Cardle sparked fears for his health ahead of the semi-finals when he pulled out of a secret official gig last night.
All the contestants remaining in the show performed at the concert for TalkTalk competition winners in London.
But 27-year-old Mr Cardle was unable to perform and could barely speak.
Together: They performed at the Hospital Club in Soho, London, from left, Matt, Mary Byrne, Rebecca Ferguson, Cher Lloyd and four fifths of One Direction, Liam Payne, Louis Tomlinson, Harry Styles and Niall Horan
He attended the event but admitted he was unable to sing - saying he had lost his voice.
He said: 'Everything has been feeling poorly recently.
'I was recording earlier and it was getting very painful, so I can't sing tonight.
Thumbs up: Cher and Rebecca pose for photographs at the special secret gig put on for a small crowd
'I just have to hope it gets better for the weekend.
'There is not much else I can do.'
The show faced a further blow after it emerged Zain Malik, 17, from One Direction, also pulled out of performing and did not even attend.
Insiders said it was for personal reasons but ruled out a death or a serious injury in the family.
Five become four: One Direction were one down after Zain Malik had to rush home for 'personal reasons'
No show: Zain, pictured on Tuesday, and right Dublin contestant Mary Byrne
It is understood he rushed home to see his family in Bradford.
A show spokesman declined to comment.
Mr Malik's bandmates in One Direction did not want to discuss the problem.
Talent: Rebecca belts out a number on stage, wearing a sparkly black dress and, right, Cher gives it some attitude
Liam Payne said: 'Zayn has got some personal problems so he is not here right now.
'We can't elaborate but we hope he is going to be ok.'
The contestants all sang at the Hospital club in Soho, London, last night.
A show source said: 'Matt is in a bad way and is trying to put a brave face on it.
If things don't improve he is going to really struggle for the semi-final and it could ruin his chances.'
Source:Dailymail