Postgraduate students in Northern Ireland will receive Pounds 1,000 less in basic support than their counterparts in England, Scotland and Wales this year. A total of 345 students are affected by the shortfall.
Hugh Baker, education officer in the student union at Queen's University, Belfast, said: "This is not right. Students in Northern Ireland should be treated with parity to those across the water."
The anomaly has arisen because the Department of Education for Northern Ireland funds PhD studentships in the province, while the research councils fund PhD studentships in England, Scotland and Wales.
Following the comprehensive spending review in the summer, the research councils received enough money to raise their PhD stipends by Pounds 1,000 to a minimum of Pounds 6,455. But Deni did not raise its stipends significantly, leaving students with just Pounds 5,455.
"It is highly unreasonable of Deni not to upgrade its stipends," said Peter O'Neill of the National Union of Students/Union for Students in Ireland. "It is our strong contention that Deni should reach parity with the research councils."
Academics are concerned that PhD students will be deterred from studying in Northern Ireland and that this will hit the local science base. Gerry McKenna, pro vice-chancellor for research at the University of Ulster, said: "It is most unfortunate that at a time when Northern Ireland is taking major strides to develop a high-technology-based economy, Deni finds itself in a position where it cannot match the level of grant support available to students in Great Britain."
The point is echoed by professional bodies. Phil Diamond, higher education and research manager at the Institute of Physics, said: "We welcome the boost to the research council stipends but the institute is concerned about the consequences for the science base in Northern Ireland."
Deni is now appealing for extra cash for next year to boost its PhD studentships by Pounds 1,000, according to a spokesman.