The report by the Patients Association, a health watchdog organization, mentions 16 incidents of people said to be left lying in their own feces and urine, having call bells taken away and being left without food, The Times of London reported online.
The association urged the British government and the regulating Care Quality Commission to instigate an "urgent review of the standards of basic care" in the hospital, plus tougher inspections and regulations.
The Patients Association said one hospital had threatened legal action if the report is published but said there was a "striking similarity between many of the cases."
One former nurse said her experience as a patient was "scary." Several examples of alleged poor care were cited in the report.
The government's chief nursing officer, Christine Beasley, defended most work by nurses and said the cases cited in the report were "simply unacceptable."