Published Saturday, 03 November 2012
Lucy Spraggan on X Factor. (© Rex Features)
Lucy was too sick to perform last week and was given a free pass.
However she remains unwell and said it would not be fair on others in the competition if she was allowed to go through again without singing.
X Factor officials have confirmed she will not be replaced by another contestant and said one act will leave the show this weekend.
Lucy said: "I am gutted not to be able to continue on this journey but I'm not well enough to perform.
You'll be hearing from me again very soon.
"To accept another free pass having missed last weekend would not be fair on the others in the competition. I wish them all well.
"I would like to express my thanks to everyone who has supported me. There is no way that this setback will prevent me from fulfilling my ambition."
Singer-songwriter Lucy, who is 20, is originally from Buxton, Derbyshire, and works as a portrait seller in Sheffield.
She plays guitar and writes her own material - and in her audition performed a song called 'Last Night' about what happened to her on a night out.
A statement from X Factor said: "Lucy isn't well enough to perform this weekend so she has decided to withdraw from the competition.
"We are all sorry to see her go and wish her all the best for the future. She has been a fantastic contestant."
Lucy's mentor, Tulisa Contostavlos, said: "I'm so sorry to lose Lucy from the competition, I have had a brilliant time working with her and I hope I can continue to mentor her in the future. I now count her as a friend as she is an amazing girl."