ONCE you've got a winning formula for a hot TV show, what do you do?

Come up with something different? Turn the idea completely on its head? Or repeat it ad infinitum, with a few not-so-subtle twists which, you hope, will keep the viewers pinned to their sofas till Christmas?

Well, we're about to find out. Popstars: The Rivals hits our screens on Saturday, so you'd best prepare yourselves for some hissy fits, pantomime nastiness and more frustrated wanabees than you can poke a stick at.

By the time the programme reaches our screens, 10,000 hopefuls will have been whittled down to just 120 by the judges. Presumably this means that the often-unhinged-looking individuals who we watched get swiftly rejected in Pop Idol have already been given their marching orders. Which is a shame because, lets face it, we all found them highly entertaining.

Still I'm sure we'll get a compilation show of the worst offenders before too long, probably released on a special edition double DVD with a commentary sung by Darius, if we're unlucky. In the meantime the focus must be on the talented, the gorgeous, the soon-to-be shining stars of the pop world.

The judges of the show are Pete Waterman, Geri Halliwell and Westlife manager Louis Walsh. What no Simon Cowell? But who will play King Rat? Well, if rumours are to be believed, Geri Halliwell has been having a go recently, with some less than welcome comments directed at a few of the hopefulls. Hard to believe that the soul-searching, self-help addicted star is really going to play bad cop to Waterman or Walsh's good cop. After all, Walsh gave us Westlife - how much more evil can you get?

While Pop Stars Hayley and Dane Bowers front ITV2's coverage of the show, queen of presenters Davina McCall will be the anchor woman of the terrestrial version, her recent work on Big Brother proving she is more than up to the task.

The twist in this reality TV tale is this added sense of competition. Of course, the singers were competing against each other in Pop Stars and Pop Idol, but they always maintained a sense of camaraderie which seemingly could not be broken by their naked ambition (Hence Darius's cringeworthy "there's a lot of love in this room" comments).

Now the show will focus on two groups, a boy band and a girl band. Cue one almighty battle of the sexes. No matter how far we like to think we've evolved, there's nothing like a boy versus girl debate to turn us into squabbling children. The producers of the show will no doubt be hoping that they can divide, and so rouse, the nation, too. Rouse them into making a few million phone calls that is.

The rivalry will also play an important part with the judges, with Pete Waterman set to manage the boy band, while Walsh will compete against him at the helm of the girl group.

Big Brother is also showing its influence, as the last 20 participants will be forced to share a house, which should crank up the tension nicely.

The last 20 will join the judges in the studios, performing live each week before facing the public vote, until eventually the final line-ups of the bands are chosen.

Then the real competition begins. Cynical minds might note that this year the show finishes on December 16, just in time for the bands to release a single and battle it out for the Christmas No.1.

It's contrived, it's dumbed down, it's juvenile, even. I know what I'm going to be watching on Saturday night...

Nicola Mostyn