Noble Vs Major: Sir John and Lady Major deny claims they are ignoring their autistic grandchild

The son of the former prime minister Sir John Major accused his ex-wife of making "wholly false and hurtful allegations" last night after she publicly claimed that his parents were ignoring their autistic eight-year-old grandson, Harry.

James Major stepped into the row after his former wife, the ex-model Emma Noble, claimed that Sir John and Lady Major took little interest in their grandchild, failing even to send him a birthday card.

James Major said: "They see him whenever he is with me and have taken a close interest in all aspects of his welfare since the day he was born. As for ignoring Harry's birthday, any or all cards or presents for Harry are always given to me. Mum and Dad have always been there for Harry – and always will be," he said.

The Majors also denied allegations that they had neglected their grandson. The claims were levelled at the couple by the child's mother, who married James Major in 1999. The union ended in an acrimonious divorce in 2003, three years after Harry was born.

Sir John's spokesman said: "They strenuously reject any suggestion that they are not responsible, loving grandparents. Harry is and always will be a profound and joyful part of their lives. Since his birth, they have contributed and will continue to contribute significantly to his wellbeing."

The allegations were made in an interview by the Majors' former daughter-in-law. "When Harry was first diagnosed, I wrote them a letter explaining what had happened, and saying that if they needed any more information they could call me. They didn't. I've written twice now, but they've never replied and I've never spoken to them about Harry's autism," Ms Noble said.

Emma Noble was best known for her role as a hostess on the TV gameshow The Price is Right when she met the entrepreneur James Major. They married in the Palace of Westminster three months after they met, in a lavish ceremony that netted them £400,000 from Hello! magazine. Ms Noble, 35, now acts as an ambassador for the National Autistic Society and is about to film a TV documentary about it.

It is estimated that one in 100 people in the UK are on the autistic spectrum, which ranges from high-functioning individuals who are less severely affected, to people who are completely non-verbal and may have a very low IQ.

A National Autistic Society spokesperson said: "If you are a grandparent that takes on some of the major caring responsibilities of looking after an autistic child – as many do – that can be very hard."