According to my own experience, colleagues and family (all my siblings work with PE in Norway), the most important thing to get an IBD-position is to achieve an internship within the IB-industry before graduating MSc. Of course, if you are ambitious and aiming to work in a bulge bracket bank right after you graduate, the school where you take your MSc is more important than your BSc. This is very ambitious, but target schools for JPM, GS, CS & MS in the UK is Oxbridge and LSE in UK. In the US, aiming for Wharton and Columbia will most likely land you an analyst role too.
How to obtain an internship position as an undergraduate? Easy, I have listed the three main factors, where number 1 is the most important aspect:
1. You have to have a solid GPA: 4.5-5.0 in a 5.0 ECTS scale.
2. Connections (alumni, recommendations etc.)
3. Be able to apply quantitative GMAT-skills on f2f interviews.
Let me enlighten #3 from my personal experience:
My first internship was as a Summer Analyst for Blackstone Group. I did not have a solid GPA, right under 4.5 approximately, but my father was a principal for BG (This sounds like nepotism, but trust me; I had to apply like anyone else).
The question I got during my interview was:
Quote:
If a and b are two primes, and a is bigger than b, how many value(s) of the pair (a,b) exist such that the sum of a and b is equal to 19? Well, the answer is pretty easy to calculate on top of your head, but my point is that it does not matter what number you conclude with; what does matter is HOW you explain yourself to the answer (If you are thinking outside the box or not). This is what landed me the internship, and I cannot emphasize how important this is.
Solution 1:Quote:
I found out that all the primes under 19 is: 2,3,5,7,11,13,17. The only possible combination is 17+2 = 19, thus only 1 value of the pair (a,b).
Solution 2:Quote:
So a + b = 19. 19 is odd, and we know from basic arithmetic that even + odd = odd. Thus, an even number added with an odd number MUST always be odd. From your question, we know that a and b are both primes. The only even prime number is 2. We know that a > b, thus b = 2.
To get a total sum of 19 when adding a and b, a must therefore be 17. Hence, it is only 1 value of the pair (a,b).
You should figure out yourself what solution would have placed you into the upper bracket or lower bracket

Remember, investment banking does not care if you can use practical arithmetic to solve problems. You are building financial models all day long, and it is therefore more important to be a number crusher.
So to sum up; if you just want an investment banking position (excluding the BB-banks), you should rather focus on improving your GPA and applying for internships. If you scored a low Quant score on the GMAT, you should study a bit further.
On the other hand, may I ask you what your GMAT score is? You claim that LSE and Cambridge are two of your possibilities as an undergraduate. On the other hand, Warwick is not a target school for BB-banks, but it is still regarded as prestigious and in the big leagues in Europe.
Regardless, it is nice to see you aiming to become an investment banker! I hope you realize that it is time-demanding, thus you will have no work-life balance. From my own experience, my life pre-IB was better than my life post-IB. Before focusing on only one sector of the finance-industry, I would advise you to explore the Internet and talk to people who has worked as an analyst/associate. I would say that the former requires a lot of source criticism, but from what I have read it is very understated. It is miserable, but the salary pays up for it

Plus, on the positive side, IBD is where it is the easiest and fastest to climb up the rankings in the hierarchy. If you have any questions, just message me or preferably write here so other aspiring investment bankers can benefit.