Concerns about management at Southern Cross care homes have been raised by the social care regulator, it emerged as the embattled company revealed plans to cut 3,000 jobs.
Of 49 homes reviewed by the Care Quality Commission (CQC) since October, it found issues with staffing levels at 19, it was reported.
Figures obtained by Channel 4 News showed that in October, a third of Southern Cross Healthcare's homes did not have permanent managers in place.
CQC director of operations Amanda Sherlock said the regulator had warned Southern Cross last year that the fact that a third of its homes lacked registered managers would be a "significant issue for the company and one that it must address".
She said: "Southern Cross as a large organisation is able to put resources into failing homes and address immediate problems. This 'parachuting' in of teams however is a short-term fix and destabilising for staff and residents.
"We would like to see a focus on continual quality assessment that prevents crises happening and provides stability and sustainable quality care."
Southern Cross blamed the number of temporary managers on the slow process of appointing permanent home managers - a process that it said was "frequently delayed at the CQC end".
A spokesman said: "At present, we have 114 submitted applications awaiting the CQC's confirmation of registration. Some of our home managers have been waiting for confirmation for over seven months.
"Additionally, I am sure that the CQC would agree that when a home manager leaves their job, it is good practice to at least put in an experienced temporary manager until a permanent manager can be appointed. This ensures greater continuity of care which is the priority for Southern Cross in all of its homes."
The Government has come under more pressure to bail out the care homes operator, whose proposed job losses are understood to include more than 300 nurses. Some 1,275 care staff, 700 catering posts, 440 domestic jobs and 238 maintenance roles could also go.