The right of hundreds of small and specialist colleges across the world to offer British degrees has been called into question by the Quality Assurance Agency.
In an interview with The THES , QAA chief executive Peter Williams warned that the widespread practice of "accreditation" - where UK universities allow institutions that do not have degree-awarding powers to award their degrees under a financial arrangement - was a "historical anomaly". The practice risked compromising quality and damaging Britain's reputation for excellence, he warned.
Institutions that award university degrees under accreditation deals include Southampton Institute, which is accredited by Nottingham Trent University, Ruskin College (by the Open University), the Central School of Speech and Drama (also accredited by the OU) and thousands of institutions overseas.
"I am not tarring all accredited institutions with the same brush and some work well," said Mr Williams. "But accreditation is the highest-risk form of collaborative provision in the sector.
"Universities should undertake such arrangements only with partners of extensive experience. And even then the awarding body does have to look after its interests very carefully with regard to the way its degrees are looked after by others."
The QAA is concerned that accreditation involves high levels of delegation to the partner. This may lead to universities losing control of the standard of degrees awarded in its name.
Despite the - usually annual - inspection by the university, annual reports by the partner and the presence of university staff on the partner's academic board, the accredited institution is largely left to its own devices.
Other forms of partnership, such as validation or franchise, which involve partner institutions awarding a university's degrees, are agreed for individual courses instead of entire institutions, and are monitored more closely.
This month, in an audit of an accreditation arrangement between the OU and a Danish college, the QAA criticised the whole of the OU's accreditation business, the OUVS, which accredits about 100 institutions worldwide. The OU accused the QAA of unfairly extrapolating from the findings of a single inspection to criticise accreditation as a general model of partnership.
Mr Williams, who is updating the agency's code of practice on collaborative provision, said: "I do not want to get involved in a public argument with the OU, although it seems to want to get into an argument with us."
Roger Brown, principal of Southampton Institute, which is accredited by Nottingham Trent, said: "It would be most unfortunate if the QAA sent out a message that accreditation agreements could not work, as they obviously can and do.
"It is true that the model represents the greatest risk because it relies on the highest amount of trust between partners. But accreditation is perfectly reasonable for institutions such as mine provided people know that is what is going on."
Patricia Ambrose, chief executive of the Standing Conference of Principals, which represents colleges of higher education, said: "Higher education colleges that are accredited in this way are mature institutions and it is a highly appropriate mechanism where good relations have been developed with the accrediting institution."