The General Secretary of the country's largest teaching union has told the TUC conference that the government is pursuing a destructive and regressive" policy on exam results.
Chris Keates of the NASUWT was speaking in support of a motion on the GCSE English results this summer.
“For the sake of the pupils concerned, everyone wants to see a robust and objective investigation of the facts behind the current GCSE controversy," she said.
"However, feedback from NASUWT members on this issue has emphasised that much of the concern within the education system is driven by the pressure school leaders and teachers are under to meet the crude performance targets imposed on them by the Department for Education and Ofsted."
The motion calls on the TUC Congress to "condemn the consequences of the changes in grade boundaries resulting in thousands of students receiving a D rather than the C they expected".
"As a result, many have lost college places or apprenticeships and may be left without access to education or training."
Ms Keates said schools that fail to meet the Coalition Government’s floor target will place them at serious risk of being forced to become an academy, regardless of the lack of evidence that foisting academy status on schools raises educational standards.
“There should be no doubt that the existence of this damaging accountability regime has nothing to do with helping schools and colleges to meet the needs of learners, but instead is simply a means by which its ideological policies can be pursued," she told the Congress.
“No other country, including those widely recognised as high performing, subjects its schools to such a destructive and regressive system of public accountability. The GCSE English controversy provides yet more evidence that the simplistic and punitive accountability regime in this country is no longer fit for purpose."