The problem only arises if the Singaporean has a different entry threshold to the Brit. If they do, and it's lower, then maybe a Brit should also be allowed to pay or better, the Singaporean should be denied access. If however, as I think most institutions would like us to believe, the Singaporean has to be at least as good as the Brit in order to gain a place, then any Brit also meeting the entry criteria should have have access to the same amount of government support/loans for the course (with extra support for poorer students).
I know some universities rely quite heavily on foreign students to boost their coffers, but I don't think any of them admit to having lower entry thresholds for them. Of course, due to foreigners having different education systems this is difficult to prove.