Well I have 4 GCSE's highest grade was a E, did not do A-LEVELS left college and started working to pay for my PPL, then did my ATPL's passed them all and I am now sitting in the RHS at the pointy end.
Point being if you are looking for sponsorship from the airlines then you will need 2 A-Levels if you are going to sponsor yourself then you don't need any academic qualifications to become a airline pilot all the airline will be intrested in is your ratings/Licence (must be at least a frozen ATPL with IR) and your flying hours.