The "outstanding" rating of an NHS trust which runs Newcastle's Royal Victoria Infirmary and Freeman Hospital has been suspended.
"Significant disparities" between the 2019 rating and findings at a recent inspection saw the ranking withdrawn, the Care Quality Commission (CQC) said.
Earlier this year, inspectors ordered immediate improvements to be made.
A trust spokesperson said it was aware of the suspension, adding that patient safety remained a priority.
She said the Newcastle Hospitals NHS Foundation Trust had received a draft version of a new CQC report, which has not yet been published, adding: "We are currently reviewing this in detail and looking carefully at issues raised."
It was rated outstanding in 2019. Then following an unannounced inspection late last year, the health watchdog ordered trust-wide improvements to be made to ensure services met legal requirements but did not issue a new rating.
Highlighting a number of problems, inspectors issued a warning notice saying immediate action was needed to improve the quality and safety of care provided to patients with mental health needs, autism, or learning disabilities.
In the report outlining the concerns, CQC inspectors said staff did not always have the skills or training needed to provide safe care to those patients, with fewer than 3% of staff having received training concerning the Mental Capacity Act and 8% receiving training about learning disabilities.
The report, published in February, said staff did not always support patients to make informed decisions about care and did not follow national guidelines to gain their consent.
However, doctors, nurses and healthcare professionals were praised for working well as a team and treating patients with disabilities or autism with compassion and kindness.
And while the trust was found to have no mental health strategy in place at the time of the inspection, one was expected to be in place by summer 2024.
'Difficult to understand'
A notice on the CQC's website said updated ratings would be published once the latest inspection report was made public.
The CQC's decision comes months after the RVI's maternity services were rated as needing improvement after they were inspected in January as part of a wider look at England's maternity care.
Then, inspectors found not all staff had relevant training in key skills and medicines were not always managed well.
In response, Dame Jackie Daniel, the chief executive of the trust, said it was "difficult to understand" the rating and that she was proud of the team for their "dedication, professionalism and caring attitude".