A London hospital's accident and emergency department (A&E) has been declared "not fit for purpose" by hospital inspectors.
The chief inspector of hospitals in England found that the department at the Queen Elizabeth Hospital, in Woolwich, was inadequate.
A report looked into the quality of services at two hospitals in the Lewisham and Greenwich NHS Trust.
The trust said it was developing an "action plan" to tackle the issues.
Exceeded waiting times
The summary of the report by an inspection team led by Dr Nigel Acheson of NHS England said: "On the Queen Elizabeth site the A&E environment is not considered by the inspecting team to be fit for purpose.
"Following admission via A&E, delays in access to investigation were witnessed, and also delays in accessing specialist internal opinion and by external transfer to specialist units."
Waiting times regularly exceeded the government's waiting target, the report found.
Inspectors also said that capacity in the department was limited and there was a heavy reliance on agency staff which led to delays in further investigation.
Chief inspector of hospitals, Professor Sir Mike Richards, acknowledged that the trust was "relatively new" as it was created following a merger in October 2013.
"The biggest problem here is in the A&E at Queen Elizabeth Hospital, which we have rated as inadequate," he said.
"Waiting times there regularly exceed the four-hour target, there isn't enough space for the number of people using the service, and the patient pathway from A&E to the ward doesn't work as well as it should."
In a statement, the Lewisham and Greenwich NHS Trust, said: "While much progress has already been made, we have lots to do and over the next month we will be developing an action plan in response to all the issues highlighted by the Care Quality Commission (CQC)."
Overall the Queen Elizabeth Hospital was rated as requires improvement, with its maternity and family planning services being declared good.
'Lack of staff'
The reports released by the CQC also covered University Hospital Lewisham, which was rated as requiring improvement overall.
Its intensive and critical care and children's care was rated as good.
CQC inspectors made both announced and unannounced visits to the sites and spoke with members of staff and the public.
In some wards, patients told inspectors they felt there was a lack of staff as it could take up to 30 minutes for call bells to be answered, the report said.
The trust was told it must make improvements in a number of areas, including ensuring that it had enough staff members to allow them to work safely and effectively, as well as reviewing the capacity and constraints for accident and emergency departments.