By now, most people would have seen and formed an opinion on Britney's comeback performance of her new track, Gimme More, at the recent MTV Video Music Awards.

With the hype surrounding her appearance reaching fever pitch before the awards show, with Vegas illusionist Criss Angel revealing that he was working with Brit to incorporate an incredible magic show into her performance, fans and celeb guests were expecting something exceptional.

But as Britney, 25, hit the stage in an ill-advisedly skimpy sparkly bra and pants, it soon became clear, judging by the shocked looks on the faces of 50 Cent, P Diddy and Rihanna, that's Brit's big night had turned into her big nightmare.

Ahlan! reveals exactly why Britney's performance was so bad and why her career probably won't recover from it...

She picked partying over rehearsals
Rather than spending every waking moment honing her performance, Britney spent the two nights before the show out in LA until 3am, partying with the likes of Paris Hilton, Pharrell Williams and P Diddy, and missed her 1pm rehearsal slot on the day.

"She didn't even get to Las Vegas until 4:30 pm. It was ridiculous," a MTV source told PageSix. "The production people at MTV were freaking out. She went to her hotel room and ordered a bunch of food and some frozen margaritas. She came down an hour later with a frozen margarita in her hand. The dance number was spectacular - without her. When the stand-in was rehearsing with the dancers, in the hours they were all waiting for her, it was amazing. Then Britney showed up and refused to do anything."

She's surrounded by ‘yes' people
Manager-less until last month, after she sacked her longtime manager Larry Rudolph, blaming him for ‘forcing' her into rehab, Britney has been acting as both her own manager and her own publicist.

Now surrounded by her PA/Cousin Alli Simms and a host of ‘yes people', whose livelihoods depend on the Britney money-making machine, Brit had no one around her willing to say "Don't do the show."

And whether she would have listened anyway is debatable. Having cut herself off from her family, including her once-close sister Jamie Lynn, Brit has no one to be honest with her.

She hasn't got ‘it' anymore
Appearing in The Mickey Mouse Club at the age of 11, Brit's been performing ever since. And now, 14 years later, it looks like the singer simply no longer has ‘it'.

"[She] seemed dead onstage," said gossip columnist, Perez Hilton. "[She's] lost that spark and shine that used to ooze out of her." And an insider told People, "She was extremely nervous. It's been a while since she's done this, and she was performing in front of all her peers, on live TV. She just got out there and froze."

Your questions, answered!

Q Why did she wear such a revealing outfit when she's not back in shape?
A A source at the event said, "MTV wanted her to wear a corset outfit. It would have looked great and covered a lot of things up, but she hated it and didn't think it was sexy enough."

Q Why did her ‘people' let her go through with it?
A "Nobody can tell Britney what to do anymore," spilled an insider. "No one can control her. She is a mess."

Q What was with the pathetic ‘dance' moves?
A A spy at the rehearsal said, "The more complicated dance moves had to be erased as she couldn't do them."

Q Didn't she realise how important the performance was for her career?
A Apparently not. "She's totally phoning this in. She doesn't seem to care how this goes. She's been drinking a bunch and not putting her all into rehearsing," said a pal.

Britney's excuse: ‘The VMAs host upset me'
Spears' camp insiders claim that Britney was informed that the VMA host, US comedian Sarah Silverman, was going to make fun of her two sons before her performance, which upset the singer.

According to sources, Brit "overheard" that Silverman was going to call Sean Preston and Jayden James "beautiful mistakes", which caused her to break down in tears. However, Silverman's rep insists, "Sarah did nothing but react to Britney's actions." With insiders adding, "The only person who knew what Sarah was going to say, was Sarah."