What is the best argument against the idea that international students ‘steal BritishWatch
But as stated fundamentally there is no such notion of "places" in any real sense. Of course, international students pay eye-watering fees to study in the UK, and universities hence make a lot more money out of them than domestic students, as the fees are capped for them and in part subsidised by the government. So if someone is arguing universities are taking too many international students you should point out this is largely due to the government limiting spending in HE for UK students, and shifting the onus for fee payments on the students by reducing the amount they subsidised student costs and increasing the amount of fees unis could charge to students, requiring students take out larger loan amounts to cover it instead.
Since I imagine the kinds of xenophobic morons making these complaints are also the same people that vote for UKIP or the conservatives though, I doubt any such argument will make any differences since by virtue of their political allegiance they are already used to selectively believing what they want to and ignoring issues directly caused by the party/parties they support.