A university department which helped make the study of modern culture a serious academic discipline is to close. The decision has angered politicians, lecturers and students.

Union leaders will consider a strike ballot next month over the decision to close the Department of Cultural Studies and Sociology at Birmingham University, where leading thinkers such as the writer Stuart Hall helped shape the study of 20th-century society.

University managers insist the decision to "restructure'' the department was essential because of a fall in research ratings and to improve standards. A spokeswoman said that all courses would continue and students would not be affected.

But the Association of University Teachers (AUT) is demanding an inquiry into the decision to close the department with the loss of 11 jobs.

The union is also considering applying for a judicial review of the decision. Undergraduates are considering legal action amid fears that the quality of their degrees will suffer. A total of 250 students are affected.

Senior academics say that lecturers from across the university will teach the modules which make up the department's courses in sociology and media, culture and society.

But students and former staff in the department say that the upheaval will damage teaching standards, which were awarded the highest possible grade five years ago.

Students are also angry that news of the redundancies only emerged after the start of the summer vacation.

The department was set up in 1964 and gained a world-wide reputation for establishing the study of contemporary culture.

Professor Frank Webster, the former head of the department, set up a new honours course in sociology, but resigned after hearing of the closure plan. He said: "You asked if students should be worried. That's why I left. I left because I could not set up this degree when the degree was demonstrably not viable."

MPs also expressed anger at the closure. Gisela Stuart, the former health minister, and her fellow Labour MP Dr Lynne Jones have taken up the case.

Ms Stuart said MPs were seeking assurances about the lecturers who would teach courses from next month and wanted to know if external examiners had approved the changes. She said: "I'm not going to second-guess the academic decision; it may be the right one. But I think the way the university has gone about making that decision has not filled me with great confidence."

Sally Hunt, AUT general secretary, said: "We are deeply concerned at what Birmingham University has done. This is a classic example of poor management leading to staff redundancies, course closures and disaffected students."

A spokeswoman for the university said the department had been restructured because its score had fallen in last year's Research Assessment Exercise, which determines the funding for research by ranking the work produced by university departments.

She insisted there had been "informal consultations" with students before the decision had been taken. A series of meetings are planned next month to discuss the changes with undergraduates.

She added: "The department received a 3a grading in the research assessment exercise. In a research-led university like Birmingham a 3a is not acceptable. We have said there is a minimum of a grade 4 required. This was the only department to drop a grade.''