Liberty X, 5ive, B*witched, 911 and Honeyz will perform an extra four dates in December, but Atomic Kitten are still to be confirmed. Vocal group Blue, who were the last act to join the show, will not be appearing.
The second run of dates has been added due to "unprecedented demand" and promises to be the "cracker of all Christmas parties".
The groups will already be singing their hearts out and reliving their pop hits when they go on a live mega-tour in May, stopping at 14 cities across the United Kingdom and Ireland.
The hit ITV2 reality show has followed the seven chart-topping groups make their return to the limelight, a decade after they ruled pop.
The final episode of The Big Reunion airs tonight (28 March) on ITV2 at 9pm, and shows the groups step back onto the stage for the first time at a sold-out Hammersmith Apollo concert.
Tickets for the December dates are on sale now and available from www.ticketmaster.co.uk or www.livenation.co.uk
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