The British Academy has strongly criticised the UK government for failing to address growing concerns about the future of postgraduate study.
In a position statement published on 5 July, the organisation warns that the lack of a postgraduate loan system and visa restrictions on overseas students are adding up to an "attack on two fronts".
"The British Academy is concerned that increased undergraduate debt will act as a major deterrent to postgraduate study, which, if left unchecked, threatens to damage the UK's higher education sector as a whole," the statement says.
"The Academy is also concerned about the potential impact of declining numbers of postgraduates on the health of UK universities - which represent one of the UK's most prized assets.
"No strategy has yet been put in place to address these threats."
Sir Adam Roberts, president of the British Academy, told Times Higher Education that although a lack of funding for UK postgraduates was "a long-standing problem", it would "probably be made worse by the fact that a lot will probably have a large debt and would be nervous about taking on more".
He added: "In effect that means - and we're already seeing this - that when it comes to jobs there will be few qualified [domestic] applicants."
In England, efforts have been made to mitigate the potential effects of increased undergraduate fees, and cuts to government funding, through an interim £1,100 top-up on teaching funds for postgraduates in some disciplines in 2012-13.
The Higher Education Funding Council for England will also bolster the research degree programme stream within its quality-related funding source from £205 million to £240 million.
But Sir Adam said that extending government-backed student loans to postgraduates needed to be openly discussed.
In the meantime, universities should make postgraduate scholarships a major focus of fundraising initiatives and industry should fund more places, he added.
The humanities and social sciences were at particular risk because they might be seen as less obvious subjects for sponsorship than disciplines with more overt utilitarian value, Sir Adam added.
However, an academic who is carrying out a British Academy-funded study of the motivations of postgraduate students has suggested at a conference that higher tuition fees may not have the deleterious impact on numbers that many fear.
Paul Wakeling, lecturer in education at the University of York, told the event, The Changing Landscape of Postgraduate Education: Improving Access, Enhancing Employability, held in London on June, that it may not be a "killer influence".
"There may be some change, but I do not think there will be a paradigm change," Dr Wakeling said.
"Whether [fees are] £3,000 a year or £9,000 might not make too much difference because the barriers are already there."
He added: "People already need to find money themselves to study. My PhD research detected [that debt] did not seem to be the killer influence."
But David Simmons, executive director of the full-time MBA at Cranfield University, added that a weak economy, fears over student visa restrictions and reduced bank lending to graduates had created a "perfect storm" for universities seeking to attract postgraduates.
More imaginative microfinance schemes, such as those being made available at Cranfield, were needed to fund postgraduate study if the state could not help, he added.