A headteacher says state school-based sixth forms are so underfunded that things have reached "breaking point".
Dominic Burke, headteacher of Balcarras School, in Cheltenham, says he is "worried for the life chances" of sixth formers after a "dramatic drop in funding" over 12 years, with the school receiving £30,000 in capital funding per year.
The Association of School and College Leaders (ASCL) said there might be a curriculum reduction and a tightening of teaching hours for students at some sixth forms to cope with "massive underfunding".
A Department for Education spokesperson said it will be spending more than £400m over this financial year to support colleges and other institutions.