Cheryl Cole - who was given her big break on TV talent show Popstars: The Rivals - will tell the X Factor hopefuls she can sympathise because she has been in their position.
The Girls Aloud star says: "I've been there and I have been here so I know how you are all feeling, I am just excited to see what you have got. [I] think it's going to be amazing and I wish you the best of luck from the bottom of my heart."
Other guest mentors include Tinie Tempah, who teams up with Tulisa Contostavlos, Ne-Yo who accompanies Nicole Scherzinger and Sharon Osbourne who is the sidekick to Louis Walsh.
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World record setting climber Ueli Steck - known for his speed at scaling mountainous terrain - has died in an accident near Mount Everest.
John McDonnell says voters can expect to see "no increases in income tax for middle or low earners" in Labour's election manifesto.
The prime minister has confirmed the Conservative government will not increase VAT if they win the General Election on June 8.