The Health regulator, "Monitor", has described Southend University Hospital NHS Foundation Trust as having the worst performing accident and emergency department in the country.
Monitor has now ordered urgent steps to be taken after it says the Trust failed to make improvements in services for its patients.
Some of the criticisms of the Trust are that it fails to see most A & E patients within four hours, which is the national target, and it fails to ensure that most have to wait less than 18 weeks for an operation.
Monitor's Regional Director Adam Cayley said. "This trust has one of the worst performing A&E departments in the country....It is unacceptable that patients have to wait. Monitor will not hesitate to step in and make changes to the leadership if the trust does not improve."
The Trust has been working with Monitor to tackle the issues since December 2012.
Southend University Hospital NHS Foundation Trust Chairman Alan Tobias, said. "We believe we are now in a much stronger position to tackle these issues and will e working hard to achieve all the undertakings and requirements we have set with our regulator."
"I am under no illusion and want to assure our local community we must and will get this right because it is in the best interests of our patients, which is what drives the board of the trust."