I want to get into investment banking

Investment banking roles don't care what degree you do, they care whether you went to a target uni or not. You could do Sanskrit at Oxford, Assyriology at Cambridge, Viking and Old Norse Studies at UCL, social anthropology at LSE, and you will have as good a chance as doing "financial econometrics" at any of them - and a better chance than someone doing "BSc investment banking for wannabes" at a non-target uni in most cases assuming both have relevant internships/summer schemes/placements etc, and do equivalently well on any assessment centre exercises and psychometric tests.

Of the unis you've listed only Warwick is a target uni. I would suggest thinking carefully about that.

The thing is Im predicted AAA and my gcses are a couple of 8s a 7 and the rest were 5s. I get a contextual at UCL so im thinking do I take the risk and apply for Economics-A*AB which 1/7 people get in or apply of PPE-A*BB 1/5 get in.

If I do that then I am applying at Warwick and UCL (cant apply to LSE as I have a 5 in English language), where else do you think I should apply to have the best chances to get into IB.

You've missed the substance of my post which was that it's not essential or even important at all to do economics or some such degree. There are undoubtedly degrees you not only meet but exceed the entry criteria for at all of those unis, especially if you are eligible for contextual offers.

Also, if you don't meet the GCSE English language requirement then you should just retake GCSE English language and give yourself more potential options.

but if my personal statement is about economics/accounting/finance then surely there isn't that many options that I could apply for. Also I am retaking my English this year and hopefully if my grades are good enough I would take a gap year and apply next cycle. However if I dont take the gap year where else should I apply beside from oxbridge,UCL,imperial or LSE