Andrew Sanders, head of Moorcroft School in Uxbridge, said many special schools are struggling to recruit staff and called for more encouragement for people to join the profession.
It comes as concerns are growing about the disproportionate impact of rising costs on special schools.
The School Cuts Campaign, which has previously published how much funding is being lost at each mainstream school, is refocusing to highlight the plight of special schools. Its website will now give funding figures for non-mainstream schools amid fears their high teacher-pupil ratios will put them in greater financial difficulty.
Mr Sanders, who was presented with a gold award for excellence in special needs education at the Pearson national teaching awards in November, said he supports the campaign for more special needs funding.
He said: “Funding is always very difficult. Because we have to have a really high staff-to-student ratio, and also because if a pupil is severely disabled they might need specialist equipment, funding is really, really important.
“At the moment we are keeping our heads above water, but I think it’s a worry as kids’ needs get more and more challenging and more and more complex. It is staffing resources that cost the most money.”
Schools are operating on budgets set before the sudden rise in energy costs, and an unexpected decision to increase teachers’ pay by around five per cent — which schools have to fund from their own budgets. Mr Sanders added: “We haven’t had to cut back on teachers. It would be something we are reluctant to do, because if you cut down on teaching assistants and teachers then standards fall, and there’s always that health and safety risk, which is a real concern.
“People don’t realise how expensive it is for special schools to run. If you buy a standing frame for a child with cerebral palsy you might be paying £4,000-5,000. And then there is the cost of maintaining them as well.
“It’s really important that young people with cerebral palsy have lots of changes of position.
“We take the view that if a child needs something they have to get it.”