Phoebe Saatchi, Nigella Lawson's 18-year-old stepdaughter, has broken her silence over her father's divorce from the 53-year-old television celebrity. The teen claims Lawson has abandoned her and has called her cold-hearted.

"Nigella has not spoken to me since she left our house on that Sunday when the newspaper story appeared. She has behaved in a very cold-hearted way. She has been my mother since I was seven or eight and has just abandoned me. That's it," Phoebe stated.

A source close to the Saatchi family has criticised Charles Saatchi, Phoebe's father, for allowing his daughter to speak to the press and become involved in a "grimy situation". However, a family friend clarified Charles Saatchi had nothing to do with Phoebe's outburst.

"She's completely devastated that she hasn't had a phone call from Nigella. Whatever issues Nigella has with Charles, she doesn't have them with Phoebe. And on top of this, Phoebe is furious with Nigella for not saying anything to defend her father and just leaving him to hang out to dry," the friend stated.

"The trouble is, Phoebe misses her so much. She was like a second mother to her, though she didn't call her 'Mummy' as she has her own mother. It was 'Nigella' or 'Nige', and sometimes even 'Darling'. And, of course, Phoebe misses her step-brother and sister, too [Bruno and Cosima Diamond, Lawson's children from a previous marriage to John Diamond]. She just finds it inconceivable that Nigella hasn't been in touch on the phone. She feels very let down," the friend concluded.

Apparently, Lawson sent Phoebe a text, after she returned to Los Angeles, asking her to come to the US; Phoebe texted back a refusal.

"When Phoebe saw an item about the invitation in a newspaper, she felt she was being used. She texted Nigella to say she didn't want to be part of her publicity machine," a source explained.

Saatchi has weighed in too, criticising his former wife for her treatment of his daughter, saying, "However disappointed Nigella may have been with me as a husband, I'm heartbroken that Phoebe has been totally abandoned in this way."

Saatchi filed for divorce from Lawson earlier this year, after she failed to defend him in public following the publication of photographs that appeared to show the 70-year-old art tycoon physically assaulting his wife.

The 10-year marriage between the couple ended in 70 seconds after the High Court issued a decree nisi.