Fans can vote to put either 2 Shoes, Amelia Lily, Jonjo Kerr or James Michael back in to 'The X Factor' from 4pm today.
With one of the acts - who were rejected from the ITV1 show during the first week of the series - set to re-enter the series for Saturday night's Queen and Lady Gaga-themed episode, viewers will be given the sole power of deciding who they want to see back in the competition.
However, none of the hopefuls will be given the opportunity to sing again before the British public chooses who will get a second shot at 'The X Factor'.
Lines will close during Saturday's episode, and all proceeds from the phone votes - thought to be at least 22p per call - will be donated to forces charity Help for Heroes.
The shock twist comes after Frankie Cocozza - formerly mentored by Gary Barlow - was sensationally axed from the competition on Tuesday.
While the changes mean one act will be parachuted back in to the competition even though they haven't battled out against their fellow contestants for the past five weeks, judge Kelly Rowland - who mentors Amelia - insists the twist replicates the "challenges" the music industry presents.
She told BANG Showbiz: The music industry is full of different changes and challenges all the time. This is just one thing that has happened that will encourage everyone in the competition to up their game.
"If I was one of them, I would be going in there and trying to blow everybody away. This turns up the energy of the competition and turns up the energy for everybody watching on television. It should bring everybody up a notch."
Gary Barlow added: "The current contestants have a five-week advantage over these guys, so it's a big challenge for them."
The successful act will be eligible for elimination from 'The X Factor' on Sunday.
X FACTOR VOTING DETAILS:
0901 616 1301 - 2 Shoes
0901 616 1302 - Amelia Lily
0901 616 1303 - James Michael
0901 616 1304 - Jonjo Kerr