AFTER four years absence from British television screens Britney Spears made a storming comeback on the X factor last night. But those fans able to look past the skimpy PVC pants and fishnet stockings were left wondering whether the long-awaited performance was all that it seemed. Indeed some fans were quickly debating on internet forums whether Britney had been miming the words to her new single Womanizer. The pop princess' energetic dance routine did not seem to interrupt her vocals - which seemed near perfect. This was despite apparent problems with her microphone, which she touched several times during the three-minute performance. A spokeswoman for the X Factor production company insisted Britney had been singing, telling MailOnline: 'There were some live vocals, but that's a question for the record company. But for those who have watched Britney go through a much-publicised breakdown, then make an astonishing return to form, perhaps it didn't matter. Louis Walsh certainly wasn't worrying about Britney's vocals. He was wide eyed as the 27-year-old bounded across the stage to a position next to the judge's table. As she bounced up and down Louis broke into a large smile. After her performance a grinning Britney told presenter Dermot that appearing on the X Factor was 'awesome' and 'amazing'. 'I love being here in London,' she gushed. Unlike guest stars Take That and Mariah Carey, Britney did not mentor the contestants ahead of last night's show. And when pushed as to whether she had any advice for them she told Dermot: 'Good luck and just keep doing it' " DM