Scores of British MBA courses could be downgraded or forced to close with the publication of new guidelines on standards by the Quality Assurance Agency.
A new national benchmark prescribing the standards of business and management qualifications at masters level says that students should have at least two years' experience of the business world before enrolling on MBA courses.
But MBA experts said that many UK providers, keen to cash in on strong international demand for the qualification, admitted students straight from degree courses with little or no work experience.
Such courses could now be criticised by QAA auditors or shut down as stricter entry requirements restrict the number of possible entrants - potentially costing British providers millions of pounds in lost tuition fees.
The QAA guidelines were produced after consultation with the Association of Business Schools, which said it had lengthy debates about setting the new work-experience requirement.
ABS chairwoman Sue Cox, dean of Lancaster University's Business School, said: "ABS is clear that we want to protect the quality of the MBA, and we believe in high standards. This is a quality check. The MBA is much more a post-experience qualification, and in order for students to achieve they need to understand the context as well as the content."
The guidance says that the learning process on an MBA should "build" on work experience, and "the experience required will be at least two years, with the typical entrant having substantially more than this".
Professor Cox would not be drawn on the number of UK MBA providers that do not meet the new requirement. Some 117 business schools award 10,000 MBAs each year. The Association of MBAs (Amba), a body that kitemarks MBA programmes, said the numbers could be surprisingly large.
Peter Calladine, education services manager at Amba, said: "Some schools are quite cynical and will accept anyone onto their courses who can pay. It is not helpful for the individual or reputation of UK education."
He said that Amba accredited 36 of the 117 providers in Britain, accounting for 56 per cent of all provision. All Amba-accredited schools insist on at least two years' work experience from students.
"Given the remaining 44 per cent of students are at 81 schools, one can safely conclude that many of the non-accredited schools must be poorly resourced operations with quality standards significantly below those required for Amba accreditation," he said.
Cardiff Business School is one provider that admits students without two years' work experience. Its website says that "applications for the full-time MBA will be considered from recent graduates or those with a similar level of qualification".
Cardiff said it would look into the matter as part of its appraisal of all schemes in business administration.