English MA with a non-English undergrad

With an undergraduate degree in classics, is it possible to go on to do an MA in English literature at a RG uni?

It's certainly possible, yes. Especially if you took some Eng lit modules as an undergrad.

Possibly. Your best bet is to contact some of the departments you're interested in and ask. If you have done work in the more literary strain of classics and have some English lit-related work which you could use in an application I'd have thought you would stand a good chance of proving you have the necessary experience.

To be honest there are certain topics and authors studied in English departments where I'd almost prefer someone with a classics background than someone with an English background. I think there are lecturers where I am who kind of really focus mostly on neo-Latin literature in their own research, and so on.

You might also find you can manage a disciplinary transition by doing an interdisciplinary masters -- I know people who have come into English by doing a BA in History, a masters in medieval studies and then a PhD in English.

Yes, I have done quite a bit of literary theory too. I hadn't thought about an interdisciplinary masters, I'll look into it. Thanks!