The singer was at the Berkeley Square Ball in Mayfair to provide backing vocals for her goddaughter Dionne Bromfield. But onlookers were shocked at how out of it Amy was, and the audience at the charity bash cringed as she grabbed and hugged Dionne as she tried to perform. The pair were joined on stage by a live band and one of Amy's backing singers for the three-song set. We're told: 'It was tragic - she seemed totally wasted. She was jumping all over Dionne as the poor girl tried to sing for the crowd. Amy didn't really sing a single note - it sounded more like she was grunting down the mic.' She then roamed from table to table, demanding to meet famous people. Sugababe Heidi Range was sent to talk to her but couldn't keep her attention long. Our spy said: 'Amy was then asked to pose for the event's official photographer, but flipped and tried to headbutt him. She looked like a woman possessed.' But backstage things took a turn for the worse. Our spy adds: 'Amy collapsed backstage in tears. She kept saying, 'Life can't go on, I can't do this'."