Former dancer Julie sadly passed away on Sunday (5 July), reportedly after suffering from a stroke.
The family said in a statement: "Today our beloved mum Julie passed away. Anyone who had met her would know what a truly special and kind lady she was. We are heartbroken and will miss her terribly, but she is now at peace."
Julie was mum to four boys - Nicholas, Simon, Tony and Michael - and step-mother to John and June.
Following the announcement, ITV bosses decided to postpone auditions, which were due to take place in Manchester today. A Syco spokesperson confirmed they will not go ahead.
The spokesperson said: "They were due to start tomorrow and carry on into Tuesday and Wednesday. Tomorrow's have been cancelled and we have not made any decisions beyond that."
Today would have seen Simon, Cheryl Fernandez-Versini and new judges Rita Ora and Nick Grimshaw together for the first time in this year's new judging line-up, as well as Olly Murs and Caroline Flack as co-hosts.