It was billed as the comeback that would bury memories of her erratic past. But while The X Factor’s Britney Spears Night attracted record ratings, it was Spears herself, not the contestants who aped her, who left viewers feeling that they had been sold short.

An audience estimated at 12.8 million tuned in on Saturday night to see the singer, who turns 27 tomorrow, perform her new single, Womanizer. But they were less than pleased with the result.

Even though her X Factor performance was a far cry from a catastrophic outing at the MTV Video Music Awards a year ago, when she barely managed to lip-synch, Spears’s decision to mime on the programme that trains its contestants to be able to perform live angered fans.

After the Spanish-born singer Ruth Lorenzo was voted out of the show, the programme’s messageboards were flooded with complaints about Spears. “It was terrible,” wrote one viewer. “All the contestants are better than her.” Another added: “She wasn’t even trying to sing.”

Spears, who was given a standing ovation by the X Factor judges, including Simon Cowell, appeared not to know anything about the contestants on The X Factor, dodging a question from Dermot O’Leary, the show’s host, about what she thought about their performances. When asked if she had any advice for competitors, she offered the sage words: “Good luck and just keep doing it.”

A spokesman for The X Factor said that her performance was “brilliant”. Richard Holloway, its executive producer, said: “We were absolutely delighted at having the American pop phenomenon that is Britney Spears appearing on the No 1 entertainment show in the UK.”

Sources close to Spears said that she had mimed to concentrate on her dancing, and felt her performance was “fantastic”. One source said: “What we promised and what she wanted to deliver was a performance where she was back to her best, and that was what she did. She’s always been known for her dancing. We’re surprised at people’s reaction.”

But Spears’s rating among her fans went from bad to worse after her presence at the GAY nightclub in London later on nearly sparked a riot. Hundreds of clubbers crushed into the venue in the hope that she would perform again. The club’s website buzzed with comments from disappointed clubbers who flocked to the venue, which has previously hosted Kylie MInogue, Cyndi Lauper and Madonna, after rumours that Spears would perform there. The singer did turn up but she remained firmly ensconced in a VIP room at the back of the venue and refused to appear on stage.

“That was the worst experience of my life,” said David Cox, one clubber. “I feel sorry for Britney, as everyone will blame her but it’s not her fault. She looked upset and then held up a sign saying, ‘Sorry, I’m leaving’.” Other clubbers writing on the GAY message board complained of people fainting and fights breaking.

Jeremy Joseph, the long-time promoter of GAY, said: “It was a nice surprise that she turned up. About ten minutes before we got a call from her management to say she was coming. We never advertised that she would be there but when she arrived I expected her to go on stage. We wanted to give her a birthday cake in front of everyone. But she just refused. It caused us huge problems. People were getting pushed.

“I don’t know why she didn’t go on. She’s really shy, and obviously she didn’t feel confident enough. I tried to persuade her but she said no. She is a lovely girl, though.”

Mr Joseph, who denied that his club was at overcapacity, was forced to come on stage himself to tell fans that the star would not appear. “They refused to believe me,” he said.

A spokesman for the star said: “Contrary to reports, Britney Spears was never booked to perform or even appear at GAY. She was invited to the evening but was never asked to perform. Following her incredible X Factor performance, Britney took up the invite and relaxed.”

Refusing to go quietly

— Lip-synching, at one time routine on Top of the Pops, has not always been badly received. In 1971 the late John Peel joined Rod Stewart and the Faces for a “live” performance of Maggie May, and pretended to play the mandolin. The Musicians’ Union was outraged and insisted that he take no payment; the fans loved it

— Numerous rockers have been forced to mime by TV producers. Noel Gallagher, of Oasis, once responded by switching roles with his brother Liam — miming the singer’s words to Roll With It while Liam, right, pretended to play guitar

— In 2004 Liam, again told to mime, backed away from the microphone and chewed gum as his voice echoed out

— On Top of the Pops in 1991, the late Kurt Cobain, lead singer of Nirvana, showed frustration at the decision to use a pre-recorded backing track for Smells Like Teen Spirit, over which he was expected to sing, by lowering his voice and changing the lyrics to tell listeners to take drugs

— In 2004 Sir Elton John, appearing at the Q Awards in London, attacked Madonna for allegedly miming. As he collected a prize for songwriting, Sir Elton laid into the singer, who had been nominated for Best Live Act, saying: “Madonna, best f*****g live act? F*** off! Since when has lip-synching been live?” He apologised three years later

— The late Luciano Pavarotti lip-synched at the opening ceremony of the 2006 Winter Olympics in Turin

— The American singer Ashlee Simpson rushed off the set of the television show Saturday Night Live in 2004 when a technical problem revealed that she had planned to lip-synch a song. Technicians had begun playing the wrong one

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