Comedian Griff Rhys Jones joined 1,000 students trying to stop the closure of Cambridge University's 100-year-old architecture department.
Griff Rhys Jones' son is a student at the architecture school
University authorities say the quality of the department's research falls below the standards expected of one of the country's top universities.
Mr Rhys Jones said since the targets were "arbitrary" and under review, the school should not be closed.
A decision on the department's future is due to be taken next week.
A spokesman for the General Board, the administrative body which controls the university's resources, said: "The General Board has advised the School of Arts and Humanities, that, in the interests of all concerned, the status quo cannot be allowed to continue.
"The board has advised the school of its considered view the department has so far made insufficient progress towards meeting Cambridge standards in terms of research quality.
"Accordingly, the board has recommended to the school that closure of the department and redeployment of the staff to other allied departments would be justified."
Mr Rhys Jones said the proposed closure was all to do with targets for research.
The presenter of BBC2's Restoration series, whose 20-year old-son is an architecture student at Cambridge, said: "It seems to me a weird decision that could possibly be made on 8 December that there should no longer be Cambridge-educated people in one of the most important professions in this country."
Staff and students at the department in Scroope Terrace insist it is the top institution in the UK, despite the fact the university says its research record has slumped in recent years.
The student protest is co-ordinated by Cambridge University Students Union, and ArcSoc, the university Architecture Society, who said the architecture school had been ranked top of the league for its teaching excellence time after time.
The school has 150 undergraduate students and about 100 postgraduates, with an average of 8.5 people bidding for each available place.