Geography or Chemistry A level for a physics(??) degree?

Currently i do maths further maths physics and geography, but i am still currently at the point where i can change geography to chemistry.

Im currently planning to apply for a physics degree, although i might do financial mathematics or engineering or something highly mathematical - but for a physics degree i was wondering if chemistry would be useful over geography as for cambridge natsci chem will increase my chances of getting in and imperial says chemistry will be useful for a physics degree.

Depending on my predicted grades im hoping to apply for imperial/oxbridge. I was wondering if chem would be benificial to get into physics at these universities?

Also, how would it affect my chances of getting in other good unis like St Andrews, bath durham etc