The competition reaches a new level as the dramatic Six Chair Challenge returns, promising amazing performances alongside agonising decisions for judges Robbie Williams, Ayda Williams, Louis Tomlinson and Simon Cowell, as they must each decide on the final six acts they will take through to their Judges' House. However, even if they win a seat, the contestants face an anxious wait as no one is safe until the last person in each category has sung. Each judge is able to change their mind at any point, swapping an act already through with someone else who comes on and out-performs them. Presented by Dermot O'Leary.