The Union of Students' Associations says hundreds of students enrolled in Christchurch tertiary institutions are trying to re-enrol elsewhere.
Union co-president Max Hardy says some might be unsuccessful because of government limits on the number of students at each institution.
He says the Government needs to act.
Tertiary Education Minister Steven Joyce says he is looking at allowing more flexibility in enrolments and funding.
He agrees that the loss of students could undermine tertiary institutions in Christchurch, but says the Government will keep an eye on things because it wants tertiary education capability in the city maintained.