IMMIGRATION Minister Chris Bowen is being threatened with legal action over changes that advantage higher education diplomas over vocational diplomas.

The changes have split the overseas student sector and sparked recriminations amid concerns students will shift from vocational colleges and TAFEs into higher education providers such as universities.

Brisbane-based private provider Kelly Colleges is seeking an injunction to stop the changes while TAFE Directors Australia is also seeking legal advice.

Kelly director Natasha Mayrseidl said the changes were "unfair" and would benefit large private provider Navitas at the expense of smaller providers.

In announcing its decision, the government said the changes had been backed by peak bodies and specifically mentioned the support of Navitas which, along with Universities Australia, has welcomed the changes.

But the Australian Council of Private Education and Training, of which Navitas is the largest member, has slammed the changes as "reckless" and warned it will spark further job losses and college closures. Navitas, whose business is weighted to higher education, has condemned ACPET's response and warned that it is now revising its membership.

Immigration last week transferred higher education diplomas and advanced diplomas into the subclass 573 higher education visa that offers applicants easier requirements to secure visas. But the department has left vocational education and training diplomas and advanced diplomas in the 572 VET subclass that generally has stricter hurdles around financial requirements.

A spokesman for immigration said the changes had the "overwhelming" support of the peak bodies consulted. But that clearly didn't include ACPET or TDA. "I am furious that the Australian government would so recklessly and contemptuously misrepresent consultations with the international education sector to justify these changes," ACPET's acting chief executive Claire Field said in a statement.

But Navitas chief executive Rod Jones said Ms Field's response was "inappropriate". He said the changes simply restored the previous treatment of higher education diplomas.

But Ms Field said that while opinions will vary among ACPETs members, "our principal concern remains that the government consultation on which the change was reportedly based did not take into account the expressed concerns of a large part of the sector, or the damaging unintended consequences".

Kelly Colleges has about 300 students studying English and business diplomas. Ms Mayrseidl said Kelly's diplomas, just like higher education diplomas, are worth up to one year's credit towards a university degree and that it has articulation agreements with five universities.

"If the outcomes are exactly the same why should it be different for vocational colleges?"

She has sent a "letter of demand" to Mr Bowen and will seek an injunction alleging unconscionable conduct.

A spokeswoman for Mr Bowen wouldn't comment on any legal matters, but said the changes were needed to align migration rules with the Australian Qualifications Framework and registration framework.

"Being out of alignment . . . means that migration legislation does not provide each education sector with the recognition it requires for each of its course types, and has the potential to disadvantage certain groups of students, as was the case with those studying higher education diplomas and advanced diplomas," she said.

TDA chief Martin Riordan said it was "nonsense" to make such a distinction. TAFEs were already "suffering . . . damage from the past actions of a small number of private colleges and the failure of the state and federal regulators to ensure they met the terms of their registration".