The NUT Edufacts 14-19 briefing paper provides a general introduction.
A more extended argument can be found in Unifying academic and vocational learning 14-19 (Martin Allen)
Social justice: a common curriculum (Terry Wrigley) also argues for a broad and balanced curriculum in years 10 and 11.
Two further comments on vocational education can be found on BERA’s Respecting Children site:
Can renewed interest in vocational education and training lead to its revitalisation? (Ann-Marie Bathmaker)