Tonight's not quite the night

After three interminable months, we've arrived at the final weekend of X-Factor. To be honest, it feels a little premature. But that's because Christmas falls on a Sunday this year, so the winner's song needs to be installed at number one a week in advance. Of course, cynics would suggest that scoring another Christmas number one is more important than establishing a robust career for a new recording artist. But let's silence those voices. For now.

We open with eerie black and white footage and a voice-over from one of the muffins, saying "To be a group in the final, and a girl group, it's just sick." I'll tell you what's sick - taking four hours to find out who's won this thing. They're going to drag this out as long as they can, so expect plenty of recaps, flashbacks and crap hats. Scratch that one, Matt Cardle's not in tonight's show. Instead, we can look forward to the finalists performing with their mentors, as the nation breathes a collective sigh of relief that we were spared the sight of Louis and Kitty giving us a rendition of Rene and Renato's Save Your Love.

With contempt and Lynx bodywash oozing out of every pore, Dermot treats us to an extended dance routine that sees him racing across London in a black cab. It's obviously a pastiche of Austin Powers, without the humour or entertainment. Dermot reminds us of that incredible recording contract that one of the contestants is going to land, hoping that none of us have read the tabloid stories about how little of the £1 million the winner actually sees.

For the second time this series we're treated to Live and Let Die, which temporarily raises my hopes about what fate will befall the unfortunate contestant who doesn't make it through to tomorrow night. Despite being slapped on the wrist by OFCOM for flogging her bottled stank, Tulisa's happily waving it around again. I guess it can't hurt now.

If we were playing cliche bingo, I'd have already scored a full house and would be onto my second glass of Gala's finest Cava - "Every step of the way," "I've come so far," and "I don't want to fall at the last hurdle". It's like a family reunion full of people you don't really want to spend any time with.

The finalists open the show with a rendition of Take That's Greatest Day, to remind us that even good songwriters can have an off-day. Amelia's sleepy eyes make her look as bored as I feel, but Little Mix are presenting themselves as a credible girl band. For once they appear to have been styled together in the same room, rather than each picking a seperate changing room and hoping for the best. After the break, Dermot welcomes us back to a "very quiet and understated final." Ha ha. That was irony. Well done to the script-writing intern who came up with that gem.

"Everybody, get... ready... for... Marcus... Collins" croaks Gary, with all the excitement of someone reading the shipping forecast. This week Marcus flew back to Liverpool in a helicopter, and revisited his school in his little red bow tie. A few years ago he'd have been bullied mercilessly for that. Now he gets a hero's welcome, so that's nice. Later on he visits his mum and is joined by Gary, who does his best 'man of the people' bit by asking for a nice cup of tea and "a gossip off Nana and Grandad." Unfortunately, time restrictions deny us the scene where Nana asks "Who's this boring tosspot?" But we did hear Grandad say "he was a little bugger". Many a true word spoken in jest.

Liverpool looks excited to be welcoming another local finalist, perhaps encouraged by the fact that Rebecca Ferguson's second placing last year didn't seem to do her career any harm. For his first song Marcus is doing Hey Ya! The performance starts out as a tribute to Catch Me If You Can, complete with half a jumbo jet sticking out of the backdrop and sixties-styled stewardess dancers. By the time they're joined by a bunch of glowstick-waving air-side staff in high-vis jackets, it's starting to look as though Heathrow is trying to sneak through their plans for that third runway without anyone noticing. Marcus has a great voice, but this song is right in the middle of his range, so it sounds flat and tuneless throughout. When the judges bleat on about song choice, this is what they're talking about. "You're what this show is all about." says Louis, and I'm starting to suspect that he's having a private joke at everyone's expense - he's secretly planning to get through the entire weekend by only using his stock phrases. "You are showing out" shouts Kelly. Come on, his trousers weren't that tight.

The move to Wembley isn't the only big change this year. Another tweak to the format has done away with the regional broadcasts, which usually involve a sports centre full of random acquaintances, and a yelled interview with a confused looking Lady Mayoress. Instead, we've got a rabble of local supporters in the crowd, being hassled by Caroline Flack and Olly Murs.

Back to Dermot, who says "Now the only remaining group, whose mentor is hoping to achieve what none of them have ever managed before..." Sadly, he's cut off before adding "...emerging from this car crash with even a trace of credibility or integrity". He's talking about Little Mix and Tulisa, who went on a whistle-stop tour of some of England's most salubrious locations: High Wycombe, Romford and South Shields. The north east is our final stop, and maybe it's just the Geordie accent, but I swear that Jade's mum described her daughter as a 'little store'. Like Budgens.

The girls enter on motorbikes, with engines revving. It's all very rock n roll, but the effect is killed somewhat as the dancers backpedal their hogs silently off-stage. They're doing You Got The Love, with a bit of Janet Jackson and plenty of Cheryl Cole in the choreography and styling. As for the girls, they're dressed head-to-toe in slashed denim, as if the cast of Prisoner Cell Block H got caught in a thresher. Louis screams "I love everything about you. Girl power back in the charts. Vote for Little Mix." He is, you know - he's having a laugh at our expense. Gary complements them on working out the "spacing on stage", and I just hope that's not a pop at poor old Jesy.

Kelly says that Amelia is ready to tear the house down, which I'm taking as a coded warning that we wouldn't like her when she's angry. Kelly and Amelia embrace in slow motion, which is probably because they didn't spend enough time together in Middlesborough to fill out the whole segment. As Amelia leaves her family home, there's a semi-naked pink man waving her on. I remember spotting him in the audience last week. Maybe Amelia sees this apparition everywhere she goes, like a camp version of The Grudge. Amelia's singing Ain't No Other Man, and although she makes a good job of it, she's no Christina Aguilera. For a start, she's about half the size. The judges mention the fact that Amelia went home, and then came back to the contest. That's the first I've heard of it. Oh God, the pink guy is here in the studio, and he's speaking. Does that mean everyone else can see him too?

The nation's hymens are about to collectively rupture as JLS and One Direction take to the stage in one giant X-Factor super group. JLS are on first, and open with their recent single "She Makes Me Wanna". I have an issue with this song, and it's the same problem that I had with Meatloaf's "I'd Do Anything For Love..." - so many unanswered questions. They're joined onstage by One Direction who perform "What Makes You Beautiful". Their collective vocal proves why no group has ever won the X-Factor.

Poor old Louis, sitting alone at the judges' table, thinking about what could have been. According to reports in the press, he's spent £30k on a hair transplant to keep up with the younger judges. Although I'm glad he didn't emerge in a wifebeater to show off a new tattoo on his arm (plugging Old Spice, natch), I question his investment in a follicular overhaul at this late stage. I have it on good authority that sticking a hair transplant on a man with Louis' idiosyncratic charms, is referred to in cosmetic circles as 'turd polishing'.

Time for the duets now. Marcus and Gary are singing 'She's Always A Woman', which Marcus has dedicated to his mum. Perhaps he should have reviewed the lyrics before making such a magnanimous gesture. They're both wearing velvet smoking jackets, which has me recalling that crushingly awkward Christmas duet that David Bowie performed with Bing Crosby. Their voices blend well together, but the standout moment has to be the lyric "She can't be convicted, she's earned her degree". And we've seen the graduation photo to prove it. Back to the audience, and someone's made a portrait of Marcus' face using Marmite on toast. As Olly takes a bite, a dark corner of my soul hopes that it's not really yeast extract that he's munching.

Little Mix say that Tulisa is the most amazing person in the world, prompting Nelson Mandela to sob into a scatter cushion and wonder about where he went wrong. It's no exaggeration to say that this is the first time I have ever heard Tulisa sing a note, so I don't know whether I'm pleasantly surprised or predictably disappointed. Thankfully, the Magimixers are doing a great job, and most of the vocal heavy lifting on their Alicia Keys medley. Or at least they were, until Jesy does a bit of awkward beatboxing that looks as though she's trying to get rid of a piece of Juicy Fruit without anyone noticing. One of the Mixers says they wouldn't have wanted to duet with anyone else, which is just as well, since it seems like the producers struggled to score any decent acts. Oh, and I take back what I said earlier - the mayor of South Shields is in the house. Which means that somewhere in the north east, his own house is probably getting robbed.

Amelia and Kelly are doing their best to show a united front, as Amelia says "I'd never in a million years think I'm pals with Kelly Rowland." Probably best that she keeps reminding herself of that, or it could get ugly. As much as I might find Amelia irritating, I have to admit that she and Kelly pulled off the best duet of the night, as they ripped River Deep Mountain High to bits. Amelia gushes that she couldn't have asked for a better mentor. Not even one who might have kept her in the competition for the entire run?

Olly tells us that someone's created a special Amelia Lily cocktail, which looks like a fishbowl of Pepto-Bismol. "What's it called?" he asks the young waitress next to him. "It's the Amelia Lily cocktail," she replies, suggesting that they spent more time chopping the fruit than coming up with a name for it.

As the technicians start tallying the votes, it's time for a couple of guest performances. First up, it's time for the triumphant return of Leona Lewis. Her pop-star status in something of a no-man's-land at the moment, but there's no denying that hers is the career to which every X-Factor contestant aspires. Tonight, she's singing Hurt by Nine Inch Nails. Coming up after the break, Tommy Steele having a crack at Radiohead. Not really - now it's Michael Bublé's turn to show us how it's done. The intro footage tells us that Bublé is the best selling male artist of the decade. Let's just pause and think about that for a moment. Happy to move on? Good, me too. It looks as though Michael has been celebrating his accomplishment with a slap-up pie or fifteen. Tonight he's singing one of the greatest Christmas songs ever made - Darlene Love's Christmas (Baby Please Come Home). Dermot asks whether that's off the Christmas album, proving that the researchers are working just as hard as the script-writer. Asked about his forthcoming ITV Christmas special, Bublé tells us that singing with Gary and Kelly was the highlight of his career. Even the judges laugh at the insincerity of this. 'Tis the season for contractually obliged appearances.

And now the moment of truth. Who's going through to the final, and who's looking down the business end of 18 months' worth of PAs at industry award ceremonies? Little Mix are through and they genuinely deserve it. Marcus and Gary are smiling, Kelly and Amelia not so much. That only gets more obvious when it's finally announced that Marcus is safe, leaving Amelia and Kelly offering up more forced smiles than the guests at someone's fourth wedding. Coming up next on ITV - Piers Morgan spends an hour interviewing Peter Andre. And for that reason, I'm out.