A crisis hit hospital could resolve its immediate issues within days but it will take far longer to tackle deep-rooted issues, an MP has warned.
Colchester Hospital declared a "major incident" last week, asking patients to stay away from its A&E department unless they have a serious or life-threatening condition and postponing operations.
This was on the back of a surprise inspection by the Care Quality Commission (CQC) on Wednesday where the health regulator raised "safeguarding concerns".
It also found that staff were struggling to cope with "unprecedented demand".
Colchester MP Sir Bob Russell, who met with hospital bosses and Health Secretary Jeremy Hunt yesterday, said he was optimistic the current situation "will be resolved within a few days".
He added: "I had a meeting with the hospital's interim chief executive two weeks' ago, and left with the distinct impression that the corner had been turned.
"What I am now hearing suggests that the corner has not even been reached.
"I am urgently raising my concerns with the secretary of state for health, Jeremy Hunt."
His comments come after the Guardian reported 563 serious incidents at the hospital over a two year period.
The figures represent incidents which are outside the normal running of the hospital, such as deaths from serious illness or expected medical complications, but they do include errors.
The hospital did not reveal the precise nature of the incidents.
Asking patients to stay away, Dr Shane Gordon, the chief clinical officer of the North East Essex Clinical Commissioning Group, said: " This will significantly help to relieve pressure on the hospital's A&E teams and reduce waiting times for all patients."
The Colchester Hospital University NHS Foundation Trust said the major incident is likely to last a week. The trust's interim chief executive, Dr Lucy Moore, described it as "a difficult time for the trust".
In July the CQC gave the hospital an overall rating of "requires improvement".
The CQC said it will publish its latest report on the hospital "in due course", and added that it will carry out further inspections at the trust.
It carried out the surprise inspection after it received "information of concern".