A stark and growing pay gap between heads and classroom teachers has been uncovered by a TES analysis.
Teaching unions see the trend as evidence of growing "pay inequality" and say it is due to greater flexibility over pay and the rise of academies.
However, heads point to the increasing demands of leadership posts as a justification for higher salaries.
In 2000, the average salary of classroom teachers in England and Wales was £23,980 64% per cent of the £37,520 average salary of headteachers. By 2015 classroom teachers in state-funded schools earned just 51% of the average pay of headteachers, home £34,600 on average, compared with the £67,300 received by heads.
Department for Education figures reported 111 academy trustees - including chief executives and principals - were paid more than £150,000 in 2014-15.