I would say English is more important. If you were to get a job with only GCSE maths and English you are not going to be an accountant unless your family works there. The only useful Maths that you learn at GCSE is percentages. I mean with GCSE maths only, you cannot really do much you need to do A level and degree level maths until you really stand you. English is needed for successful interviews, a good personal statement if you are applying to university it is the creative part of life which is just as important as objective facts.
I would also say that while maths is universal, if you cannot speak the language it is useless it is not like knowing maths = everyone understands each other.