The Coalition has been accused of cynically using overseas students as cash cows after claiming it will raise an additional $3.5 billion from increased visa fees and extra taxes from allowing them to work 30 hours a week, despite its promise to slash the number allowed to come here.

In its election costings released on Thursday, a surprise line item revealed that a Coalition government expected to raise $460 million over the next four years in additional taxes by allowing overseas students to increase their work hours from 48 hours a fortnight to 60 hours.