I completed my ATPL without A-Levels and also employed sitting in the pointy end.
The advice above is good, if you are looking for sponsorship then there is no way a airline is going to pay for it without A-Levels at the least.
I kid you not it is very hard work and there is a lot of it and once you get your first job you find it's a career of on going exams and tests, it never stops.