I read it was current affairs. To prep, reading a quality newspaper (not the Daily Mail, tis shite) like the Telegraph or Guardian. It'll be putting an argument forward, so some argument practise if you don't argue much would be good (top tip, parents are best lol)
I'd disagree slightly with McFlurry; you want to be reading a range of papers, not just those on one side of the political spectrum. By all means read the Grauniad or the Indy, but balance it up by reading a more right of centre paper, like the Torygraph or Thunderer (The Times). Try and get an appreciation of both sides of a given argument, decide which you think is right and your reasoning why. If you want, set yourself a question or two and practice, although as long as your spelling, grammar, punctuation, and sentence structure are ok, you'll be fine. Try and use paragraphs as well: it's just easier to read!
Personally, I'd just read one newspaper, watch the news a few times and perhaps delve into the Economist once in a while (although that last one may be kicking the arris a bit). Grasp the main issues of the day and develop the semblance of an informed opinion. When asked what paper you read, I wouldn't speel of a long list of titles that you think they want to hear. Papers may well be representative of a particular political bent but you'll be expected to understand that and read through the 'ganda, sorting wheat from chaff. The politics may be different but the stories are essentially the same. Being prepared is one thing; having a life is perhaps something else.
As a hopeful 6th form scholar, I can't go overboard on preparation, because I have GCSEs to consider, and going on facebook, getting drunk and nicking traffic cones to fit in as well. But time there is, but probably not enough to read 2 papers daily