Six children die in custody plot that went 'horribly wrong', court hears LONDON: A British couple accused of killing their six children in a house fire started the blaze themselves as part of a "plan that went horribly wrong," a court has heard. Prosecutors claim that Mick Philpott, 56, and his 31-year-old wife Mairead set fire to their house in Derby, in the Midlands, last May in a bid to frame his ex-girlfriend and claim custody of the four children they had together. The Philpotts, along with a third defendant, Paul Mosley, 46, each denied six counts of manslaughter at Nottingham Crown Court on Tuesday. As their trial opened, Mr Philpott tried to leave the dock as the jury listened to the telephone call the couple made to emergency services when the fire took hold in the early hours of May 11. Mrs Philpott was heard screaming on the tape, while her husband told the operator: "I can't get in." The jury heard that neighbours tried to rescue the children, aged five to 13, but were overwhelmed by smoke and flames. When police carried the children's bodies from the house, their father had to be restrained. "It must have been quite clear the plan had gone horribly wrong," prosecutor Richard Latham told the court. Mr Philpott was overheard at the hospital saying: "It wasn't meant to end like this." Police later made secret recordings of conversations between the couple. In one extract, Mr Philpott told his wife: "Make sure you stick to your story." The jury heard that the fire broke out on the morning Mr Philpott was due to attend court with his ex-mistress, Lisa Willis, to discuss where their children should live. He had made numerous reports to the police that Ms Willis had threatened him and his family, Mr Latham said. The family had previously lived under unconventional arrangements, with Mr Philpott, his wife and Ms Willis sharing a home with the 10 children, plus a child Ms Willis had by another man. But Ms Willis had broken up with Mr Philpott three months before the fire and taken her children with her. The court heard a fortnight before the tragedy, Mr Philpott had told friends he had a plan that would help him win his children back. The trial continues.