Patient safety will be harmed and victims of medical negligence denied justice because of flaws in the government’s Health and Care Bill.

Speaking to the Guardian, Rob Behrens, the Parliamentary and Health Service Ombudsman, said that his staff would be unlikely to be able to get to the bottom of clinical blunders because he will be denied potentially vital information collected by the NHS’s Healthcare Safety Investigation Branch (HSIB) under the bill.

The legislation opens the door for the HSIB to ‘operate behind a curtain of secrecy’ and therefore undermine Behrens’ investigations into lapses in patient safety. This, he said, could deny grieving families the full truth about why a loved one died.

Both the HSIB and ombudsman publish reports into areas of inadequate NHS care, such as care of people with learning disabilities. The HSIB was established in 2017 to improve patient safety after the Mid Staffordshire NHS trust scandal. Under proposals in the bill, it would be put on a legislative footing and renamed the Health Service Safety Investigations Body (HSSIB).

Julia Neuberger, a crossbench peer who chairs University College hospitals NHS trust, has tabled an amendment to the bill in the House of Lords seeking to give the ombudsman access to information obtained via ‘safe space’ processes. Evidence about mistakes given privately in a ‘safe space’ to the HSIB cannot be shared with anyone else except coroners.