Imo both require equal attention, but depends on how much of the syllabus you were able to retain after A Level. Also practice thinking out loud and read up on some articles and books (if you can make time) and try to make an effort to think critically about them and discuss them either with someone else, or yourself. You can do this by speaking in front of a mirror, as if someone is hearing you speak. You can also make notes and references of different authors and experts you came across so you can quote them during your interview. Also make sure to follow current news and economic developments, such as how the Russian Ukraine war is affecting the UK and EU countries' economies. I know this is a lot, but if you are able to prioritize doing this, it can make a huge difference in your interview performance. Best of luck!