Once again people replying don't know what they are talking about.
I am in OP's position in a couple of years time. I got ACD at A level thanks to mental health problems so am at a 'low' university. These A levels were not a representation of my intelligence but of my circumstances at the time. I persued the subject I got an A in and I've worked hard so am now on the border between a first and a 2:1 - a real representation. Despite having poor A levels, some poor first year grades and at a low uni, I have MSc offers from Birmingham and Newcastle. Because guess what, how you are performing in second and third year of your degree is what really counts regardless of your institution. And to get on to those MScs I only need 60 overall for Birmingham and 50 overall for Newcastle. OP just work hard and you can apply anywhere. And don't think it will be easier because you are at Portsmouth. It will only be less intense in first year and if you hand in a poor piece of work you will get a poor mark.