law

what subjects and grades do you need to do law and become an mp etc..

Not really any one answer.
Check individual universities for law requirements. Any decent unis require mostly straight As. Though I guess there are lower unis, or even other way to get in.

No subject requirements, though academic, hard subjects preferred, maybe an essay subject like history / eng for good measure.
Personally I did math, physics, economics and politics.

Becoming an MP? Absolutely no requirements...