Patient care has improved at the trust since March, the CQC said
A hospital trust which was criticised for its high death rates is not improving quickly enough, a health watchdog has said.
Mid Staffordshire NHS Foundation Trust had not recruited enough permanent nurses in the past six months, the Care Quality Commission (CQC) said.
The trust said it was working hard to improve its staffing levels.
The CQC's predecessor, the Healthcare Commission, said in March patients had died "needlessly" at Stafford Hospital.
Its report said emergency care had been "appalling" and up to 400 more patients died at the trust than would have been expected to between 2005 and 2008.
The CQC said in its six month review of the trust that mortality rates were declining and were at least 1% lower for emergency admissions from January to June compared to the same period last year.
It said patient care had improved at the trust since the critical report and it was now "taking seriously information about mortality rates".
But it said there was still too much reliance on agency nurses.
It said patients were being discharged too slowly and the trust needed to communicate better with the local community to build public confidence.
Andrea Gordon, regional director for CQC in the West Midlands, said: "Permanent staffing levels remain a concern and this must improve.
"Although there had been some change, there was still a shortfall in permanent nursing staff and the trust was still using bank and agency staff to supplement numbers.
"We are aware that the trust is working to address these issues but there is still some way to go."
The trust's chief executive, Antony Sumara, said the CQC had found "steady progress" but the trust was "not complacent".
He added: "We are working extremely hard on our campaign to recruit more nursing staff so that we can reduce our reliance on bank and agency staff.
"I would like to encourage nurses to come and see what we have to offer as an employer and hope that they will want to help us become one of the best hospitals in the country."