The Government is defending the effect its changes to student loans and allowances will have on thousands of post-graduate students.
From next year, the Government will cut access to allowances after four years' study.
The Labour Party says only wealthy people will be able to do post-graduate study.
Tertiary Education Minister Steven Joyce told Parliament on Tuesday about 4000 or 5000 post-graduate students will be affected by the law change.
However, he says those students will most likely have a significant income premium over others who do not go to university.
Mr Joyce says post-graduate students will still be eligible to borrow from the student loan scheme.