Peter Dutton’s promise to cut the number of overseas students, especially in world-class universities, to free up housing for locals would wreak havoc on the $51 billion export sector while sanctioning poor-quality, non-genuine students in private colleges, business and industry leaders say.

The opposition leader pledged to cut the number of new overseas enrolments by a further 30,000 than the 270,000 cap Labor tried to impose last year before the plan was gazumped when the Coalition and Greens teamed up to stop the legislation.