It is a shame you’re not a woman Simon, like Jane says, the hormonal argument is always a good one, along with planning pregnancy. But we can’t really do anything about you missing that all important second X chromosome, so you might have to major on the job argument.
Bear in mind the GP won’t be able to put you on a pump, the only thing they can do is refer you to a hospital, so might be worth doing your research into where the best pump clinics are near you and asking to be referred to that one. INPUT have a list of pro active pump clinics they know of, but its not an exhaustive list so if there’s not one near you, might be worth emailing them and asking if they know of any near you that are ok or any that should be avoided. http://www.input.me.uk/alt-insulin-pumps/pump-clinics/