The South Eastern Regional College of Further Education has been heavily criticised for the way it runs its Essential Skills courses.
Inspectors were brought in to investigate the teaching of literacy, numeracy and computer skills following complaints by lecturers at the college.
They criticised middle and senior managers.
But the college has argued that this was "a snapshot" inspection and not a reflection of student success rates.
The rates which stand at 63% are "above the sector average", they said.
The inspectors went to four college campuses to watch classes, check paperwork and talk to lecturers.
They said the provision for students was inadequate with the flaws outnumbering the strengths.
They found the teaching was mostly good or better, but they said some classes were very crowded and a wide variety of abilities were being taught together.
They said a decision to reduce the time spent on students was taken without a clear reason and they said managers had insufficient and irregular communication with staff.
Jim McKeown of the University and College Union (UCU) said lecturers were concerned about some of the practices put in place by managers at the college.
"We took those concerns to the Department of Employment and Learning. They asked the inspectors to have a look at it. They have done that and the report vindicates all the concerns of our members," he said.
The inspectors will monitor the situation for the next year and a half.
The college director declined to be interviewed but a spokesperson said the college had been going through a period of change when the inspection was carried out.
In a statement, the college said the results of the snapshot inspection were not a reflection of student success rates which, at 63%, were "above the sector average".
"In order to improve on the learner experience and ensure more people succeed, SERC staff have been implementing a complex and labour intensive change management process since September 2010 which was still underway during the snapshot inspection," the statement said.
"Most importantly, processes are being embedded to ensure that students, who may have had poor experiences of English and Maths at school, are being properly supported during their time at SERC."
The college has invested heavily in services such as SERC Extra which is unique in the sector and in pastoral care, the statement said.
"Our focus is, and always will be, on ensuring the best possible learning experience for students to help them get the best result."