I am thinking of applying for a Masters at either Oxford or Cambridge. The problem is that I am currently attending a lower tier university (a former polytechnic to be precise). Even if I get a first or 2:1, will I be a competitive applicant?

I think it depends entirely upon your application, your grades, your research proposal, and your references. I got offers from both Oxford and Cambridge for Masters and they have very extensive application forms but I think what they are really interested in is your research potential and I think they judge that mostly by your research so far (your current grades and dissertation project) and your proposal for what you're going to research at Masters. Definitely worth a shot in my opinion. But bear in mind that even if you get in they will expect you to be able to prove you have upwards of £18,000 sitting in your bank account to fund yourself. This is why I actually ended up going to a different Russel Group university because they offered me full funding and I couldn't afford to go to Oxford or Cambridge self-funded. Good luck!

Possibly if you get a first. Apply anyway. Plus, if you're paying, masters are fairly easy to get on to.

I agree with TreeofLife - if you are paying you'll most likely get in. A friend of mine did his Masters at Cambridge and did not have a Bachelors.

I can't speak for Cambridge and I've never been a student at Oxford, but I have worked in the Graduate Admissions Office at Oxford. When I worked there - granted a few years ago - it wasn't the snobby entrance requirements you'd think - usually if a professor or a faculty was interested in you and you had at least a reasonable first degree, you'd probably be given some sort of opportunity.

My first degree is from an old teacher training college (decades ago!), my first MA is from a middle-of-the-road American college, my second MRes will be from a lower tier British university, but I'm still considering applying to Oxford. To be honest, I have no idea if I'll get in or not (I already have a PhD place somewhere else), and the only reason I'm holding back is that I have a family attached to me and I can't afford Oxford house prices.

But you've got nothing to lose and everything to gain and if you are interested in Oxford or Cambridge, just apply.

Aim for a first and apply, you should get in with good references. I know plenty of people who did. They are no where near as strict with Masters as bachelor entry.