Six young builders from previous shows team up with celebrities to do battle in a range of festive challenges, including Rob Beckett, Warwick Davis, Joel Dommett and Alice Perrin

Alex Horne, Sophie Duker, Sophie Ellis-Bextor, Scarlett Moffatt - and their little helpers - compete to design, build and model a LEGO Christmas jumper, and make a magical giant LEGO snow globe