Students and lecturers at the University of East Anglia's school of modern languages and European studies this week protested about the downgrading of marks awarded to more than 300 students for coursework.
Some students have had their grades reduced by nearly 10 per cent, even after external examiners had moderated the standard, leaving them with results one class lower than they had expected.
Students think the changes stem from criticism by external examiners last year, when 88 per cent of the European school's graduates received firsts or upper seconds compared with 66 per cent for the university as a whole.
Lecturers at the European school forced an emergency meeting of the governing board on Wednesday afternoon.
An internal memo by disgruntled lecturers said: "The level of demoralisation among both students and teachers is very high and we feel that the only way to try and improve the present confused situation is for us to discuss the issue and to try and gain some agreement as to procedures." It added that "in the light of the anomalies produced by 'scaling' that grades for semester 1 be those returned by the teachers and externals".
Students organised all-day protests on Wednesday, including a sit-in in the arts buildings and a rally in main campus square. A petition with more than 200 signatures was delivered to the Derek Burke, vice chancellor, last Friday.
Daniel Owen, student union academic officer, said: "The adjustments have been made without anyone looking at the students' work."
Professor Burke has ordered an inquiry chaired by pro-vice chancellor Martin Hollis to report by Easter. Students will get an interim report before March 24.