Lulu, who famously collaborated with Gary on Take That hit Relight My Fire, will help the three permanent judges whittle down the groups to five final bands who will go forward to compete in the live shows.
Updated 14th September: It has just been announced by the BBC that Martin Kemp and Dannii Minogue are to join Gary Barlow as judges on BBC One's Take That talent search Let It Shine which will be co-presented by Graham Norton and Mel Giedroyc
Kemp, an actor and Spandau Ballet's bassist, will be a permanent judge, as will the Australian actress and singer.
Amber Riley, best known for her role as Mercedes Jones in Glee and shortly to star in Dreamgirls the Musical , will be a judge in the first stage of the competition.
Auditions took place in July and August this year and filming began this month.The talent show is set to be broadcast on BBC1 starting in January next year with Barlow as the main judge who will be joined by three mentors each week.
Barlow is searching for five performers to star in a stage show called The Band which is being created in association with Barlow as well as Take That's Mark Owen and Howard Donald. It will initially tour the UK.
The BBC have said they aren't looking for lookalikes. Instead they are seeking people who “can sing and move as well as the original members of the group”.