There are 48 acts left but by the end of the night there will only be 6 acts left in each category.

First up to face the judges in London's West End are the boys.

The first contestant to front up is 14 year old Luke. He sings Let It Be and Dannii thinks that if they put him on the live stage he'll fall flat on his face. Simon puts her in her place though and asks her what she would have done had she been told that at 14. She has no reply. Luke is in tears as the tension is pretty tough.

There were plenty of nerves from the boys and Simon is worried that this group isn't going to be able to cope.

Next up is Andy who sings I Can't Make You Love Me and he's really good.

Ridian performs Let It Be and Sharon has her head in her hands. The judges think he's in a differnt league and Sharon is forced to agree.

The judges then have to tell the boys who is in and who is out.

It's time for the girls to perform one of 10 songs to perform. Kimberly is excited to get out on the stage to perform One Moment In Time. She annoys the judges but she did well and they like her.

One of the judges favourites, Annalisa, makes a real mess of Torn as she forgets the words. She's embarrassed and the judges are incredibly disappointed. She's not the only one struggling with the words though.

Emily sings Sorry Seems to Be The Hardest Word but she's flat and sounds terrible.

The judges then pass on their verdicts to the girls before it's time for the groups.

There are some clashes within Hope but they seem to pull together and sing I'll Stand By You. Simon isn't impressed and can sense that there was something going on.

South London trio, Ghost, are really hoping to keep it together and nail this performance. They sing Ain't No Mountain High Enough and the judges like them but Simon thought they were a little old fashioned.

It's time for another verdict from the judges before the Over 25's have their final shot at securing a place in the next round.

CK sings You're Beautiful while Gav sings Your Song.

Louis doesn't want the over 25s group as he thinks it would be too much work and he can't offer them what they need.

Beverly sings Let There Be Love but Simon thought it was too safe.

It's time for the final decision and who will be mentoring which group.

Simon, Sharon, Dannii and Louis are given envelopes with directions to their room which has their group in it.

Simon goes to his room and finds the Groups inside. Sharon gets the girls. Dannii gets the boys and Louis gets what he didn't want - The Over 25s.

Next week the final audition takes place at the homes of each of the judges in Dublin, Ibiza, Los Angeles and Marbella where the judges must reduce their 6 to 3 before the 2007 X Factor Top 12 can be revealed.