Overseas academic visitors to the UK may be granted leave to remain in the country for only three months under proposals being considered by immigration authorities.
Visiting scholars, who may be on sabbatical leave from an overseas university or taking part in an exchange, are currently allowed to stay for up to 12 months. Under plans being considered as part of the new national points-based system for migrant workers, this period could be reduced.
Universities UK has objected to the proposed change, pointing out that many visitors want to stay for a full academic year. A final decision is expected next month.
Catherine Marston, a UUK policy adviser, also expressed concerns about proposals to categorise sponsored researchers as "tier 5" migrant workers.
For staff falling into this category, the would-be employer must pass all information relating to the worker's identification, attendance at work and contact details to a third-party organisation.
Speaking last week at a conference on the new laws at the University of Warwick, Ms Marston said: "We do not understand why sponsored researchers should be treated differently."
Not only would the involvement of a third-party body add to university bureaucracy, she said, "We know of no organisation in existence that would be willing to act as a third-party organisation."
The conference also heard that requirements to monitor academics' attendance were likely to meet angry resistance. From 2009, universities will be expected to inform immigration authorities if overseas academics have been absent without permission for more than ten days.
"Our academics work abroad, from their second homes, all over the place," one delegate said. "If they are line managers, how would they know if someone is in the university or not?"
The recruitment of external examiners was also raised as a concern. Several delegates said a requirement, which came into force this spring, for employers to check original identification documents before examiners started work was too onerous.
One said that such requests had been met with responses such as "You cannot be serious."