My Y9 DS has appalling handwriting and terrible spelling. This has been the case for some time. In Y5 and Y6 I was told not to worry about the spelling because the SAT's only accord a tiny percentage of marks to it, so best to concentrate on other areas!! 
In Y7 at a new secondary school I flagged the issue up with head of English and felt placated for a while. However, Y9 has seen a new level to his scruffy presentation. DS's work appears to reflect a real disorganisation and lack of care, but even his teachers say that the content is actually there, it's just deciphering it is the problem. DS has always struggled as a left-hander - smudging work, not being able to watch what he is writing, but I feel progress should be possible by now. Also, taking the 'well, he's a 13yr old boy, what do you expect?' line is also not acceptable.
He is doing himself such a disservice by not attending to care with his writing. At home, DH and I have attempted in the past to give DS help with handwriting but I'm the first to admit we are not consistent and therefore have not made any impact.
I contacted head of English yesterday and voiced my renewed concern, saying that I was willing to give my son handwriting 'lessons' at home and that I would get a list of y9 spellings off the internet, (willing to give it another go!) but what could the school offer? I was told that the issue had been passed on to pupil support who are at this time making a list of pupils for assessment to see who will need a scribe for GCSE's. I think this was meant to make me feel reassured. However that to me is shutting the door after the horse has bolted and is not really supporting my son in TEACHING HIM HOW TO WRITE!! 
Any ideas as to what I could do? And how much can I demand of the school? Ideally, I would like him to have some one to one handwriting sessions after school, AT school. I guess lack of funding will be the excuse for not offering me that.
Wish I was one of these people who managed to cover this sort of thing at home - filling in the gaps that the school doesn't address - but I also feel strongly that the basics of writing is what the education system should be in charge of. I'm furious with the primary school to be honest (and myself for not getting it sorted years ago).