Shadow health minister Emily Thornberry has demanded an independent inquiry into allegations of abuse at Winterbourne View care home.
Asking an urgent question on the subject on 7 June 2011, Ms Thornberry said "full and frank answers" were needed after undercover filming for BBC Panorama appeared to show evidence of serious abuse at the private care home near Bristol for people with learning disabilities.
"Whilst internal investigations conducted by the CQC and the South Gloucestershire Council, both bodies directly connected with this failure, will be of some value, they are nevertheless insufficient," she said.
"We are asking for an independent inquiry, similar in nature to the well-respected Healthcare for All (inquiry), that was conducted by Sir John Michael in May 2007."
In response, Health Minister Paul Burstow said the government had not ruled out ordering such an inquiry.
But he said ministers wanted to have all the facts of the case before deciding whether to order a full independent review into the care of adults of Winterbourne View residential hospital in Gloucestershire.
Mark Goldring, chief executive at the charity Mencap, would be helping officials at the Department of Health investigate the findings of inquiries by the Care Quality Commission (CQC), England's regulator of health and social care services, and the local council, Mr Burstow added.
There was also a criminal investigation by police to consider before deciding on whether to launch an independent inquiry, he said.