A ban on staff wearing jeans and combat trousers has been issued by a trouble-shooting principal who has ordered lecturers to dress smartly for work.
Bill Grady has introduced a strict dress code for staff at a college rated inadequate by inspectors last month.
He insists all male lecturers wear jackets and ties or clean overalls, and he is demanding women dress "professionally" and "do not expose too much flesh".
He issued the edict within weeks of taking over as principal of North East Surrey college of technology in Epsom, where he is also planning 40 redundancies.
He has been hired for six months to launch the college's recovery after six out of 11 curriculum areas were graded unsatisfactory in its inspection report.
"The dress code was one of several things I realised I needed to bring in when I walked in here on my first day," he said.
"I bumped into one male lecturer wearing jeans and flip-flops. I explained to him my expectations and my reasons for them. He came in the following day properly and appropriately dressed and has been that way ever since.
"I expect to tell the difference between staff and students. More importantly, students should feel that the people who are charged with their education have made an effort and are setting an example."
He said there will be consultation on the issue and claimed the dress rules have the backing of the "vast majority" of staff.
"They are overwhelmingly in support. I have had nothing but positive feedback in staff meetings," he added.
Natfhe, the lecturers' union, described the dress code as "petty". Mary Cooper, Natfhe regional official in the South-east, said: "This will only demoralise lecturers ahead of the 40 redundancies.
"I am shocked he has taken it upon himself to criticise lecturers' dress at such a difficult time.
"We have not heard of any edict from Surrey learning and skills council or the Government about this. To me, lecturers at Nescot do not differ in appearance from those anywhere else.
"Many lecturers, despite their modest pay, make every effort to appear smart. The principal should also remember that Nescot has not implemented the national pay agreement."
Dan Taubman, the union's national official for education, said: "Natfhe is shocked that the acting principal should be so petty. What matters is the quality of teaching."
One Nescot lecturer, who would not be named, said: "The acting principal seems to be implying that many lecturers were not smart before and were somehow failing the college through their dress.
"We would argue casual dress is not the same as being dressed sloppily.
"We are trying to make relationships with the students and we want to pull down barriers, not put up new ones."
Mr Grady said he also imposed a dress code for lecturers at his previous posting, the Isle of Wight college, which was described as "the worst college in the country" by the then lifelong learning minister Margaret Hodge before he took over.
He was awarded the OBE in January 2004 for his work in turning it around.
He said he had also ordered a clean-up of Nescot's grounds and walkways.
"Within a month the estate looks brighter and cleaner. There is a buzz about the place that wasn't here a month ago," he added.