Leon Mallet, Alisah Bonaobra, Jack and Joel and Talia Dean will return as the 'X Factor's wildcard contestants.
In a twist during the Judges Houses' episode last weekend, it was revealed that the public would have a chance to vote to put their favourite act from each of the four categories - the boys, the girls, the overs and the groups - through to the live shows to join the 12 acts who had already been chosen by the judges, Simon Cowell, Nicole Scherzinger, Louis Walsh and Sharon Osbourne.
A source said: "Few things divide fans like previously axed contestants being given another shot, but the public have spoken. After voting closed on Monday, Leon, Alisah, Jack and Joel and Talia were told they'd nabbed the four remaining spots.
"They've all been favourites throughout the season, and as we've seen in years previously, could well go on to be the show's most memorable acts. They're all beyond excited and are working tirelessly to prove viewers got it right and that they are worthy of a spot."
And show bosses have changed the format of the live shows in one of the biggest shake-ups by introducing a "money-can't-buy prize" that the top two contestants take part in a sing-off to win.
The insider added to The Sun Online: "They feel introducing a sing-off between the top two will be a huge hit with viewers who will get to watch their favourites sing again each week, while the aim of winning a money-can't-buy prize will add that classic Saturday Night entertainment feel that ITV's most successful shows, such as Ant & Dec's Saturday Night Takeaway, have."
The 'X Factor' continues on ITV on Saturday (28.10.17).