I can't comment on your situation, but I'd strongly advise you against applying for this course if you want to learn proper economics at university. I've looked at this Econ/management course at KCL before and it's a complete joke. There's no A-level requirement for maths (something that any decent economics course should have) and they give you marks for literally turning up for class (this isn't America!!). Oh and did I mention that King's doesn't even have an economics department?! It's administered by their business or management department or whatever.