Inspectors have ruled that the People's College, Nottingham is unsatisfactory, with five curriculum areas judged weak, and two poor.
A joint OfstedAdult Learning Inspectorate team went into the college in January. The college received the draft report early this month.
Stephen Hyde, chair of the corporation, said: "The overall message is that we have not been delivering the standards that we thought we were and we are unsatisfactory in too many areas."
John Rudd, principal of the college, reported to the board on feedback sessions held with the inspectors.
He told them "It was apparent that in some areas there was a pedestrian style of teaching of theory subjects, and too much teacher-dominated teaching. This was in contrast with good workshop and practical delivery.
"It appeared that any positive comments in relation to teaching had been offset by issues of concern about retention. Retention had been the main focus of priority for inspectors...it was not confined to level 1 learning (five GCSEs at grades D to G) but was being experienced across the range of programme levels."
Although governance was judged as good, leadership and management were thought to be unsatisfactory because of static retention rates had failed to improve.
The board agreed to form a task group on retention and achievement.
In financial terms the college is doing better. A revised three-year financial forecast predicts that it will achieve a surplus this year and for the next two years.
The college has complained to the Nottinghamshire Learning and Skills Council about errors in its consultation document on the possible merger of People's, South Nottingham and Broxtowe colleges.
They said the LSC had given the false impression that People's supported the merger, and made no mention of the possible merger of People's and South Nottingham as an alternative.
A spokeswoman for the college said the inspection was confidential and they were unable to comment. Details can however be found on the college's own website at www.peoples.ac.uk, under board minutes for January 26.