(Reuters) - Prime Minister David Cameron said he would look "very closely" at the case of a severely disabled girl whose mother has accused him of going back on a pre-election promise to ensure more help for families like hers.

Riven Vincent made headlines on Thursday after revealing she could not cope with looking after her six-year-old daughter Celyn, who has severe quadriplegic cerebral palsy, and had asked social services to take the girl into care.

It came after she learned that her council could offer no more than six hours respite care a week.