All applicants to British colleges and universities, irrespective of nationality, are obliged to submit confidential school references. This arises because applications are processed initially on the basis of predicted results and provisional offers of places are made on the basis of these results. The school reference includes, inter alia, a prediction of expected results. Applications to third level institutions here are processed solely on the basis of actual results so the question of references does not arise.
The question would seem to imply that only Irish nationals are obliged to submit confidential references. This is not the case, all applicants, including British applicants, are obliged to submit confidential references.