The health watchdog has "serious concerns" about the care of children at a scandal-hit hospital.
The Care Quality Commission said "rapid and sustainable improvement" is needed at Basildon and Thurrock University Hospitals NHS Foundation Trust in Essex.
The watchdog has also ordered an independent investigation into the paediatric services provided by the trust.
During an unannounced inspection earlier this month, the CQC noted that there were problems with waiting times, the numbers of senior staff and out-of-date medicines.
"The trust was found to be failing to plan and deliver care to meet the needs of children in a way that ensured their welfare and safety," a spokesman said.