Academies in England received less last year per pupil in secondary schools than four years earlier, according to official figures.
The median income per secondary pupil in academies for 2015-16 was £5,714, down from £6,340 in 2011-12, not taking into account inflation.
Head teachers have been campaigning about funding shortages.
But last week Education Secretary Justine Greening promised to reallocate £1.3bn more for school budgets.
The figures from the Department for Education show a £280m shortfall between total income and…