Fourth-year students have become the "most tested generation ever" as the botched introduction of new exams threatens Curriculum for Excellence, the head of Scotland's largest teaching union was due to claim today.
In a damning speech, Phil Jackson, president of the EIS, was expected to say that S4s faced "the spectre of failure" because the reality of the new Nationals flew in the face of the basic principles of CfE.
He was also due to tell ministers and officials at the union's annual general meeting that they must learn tough lessons from this year's difficulties and "get it right next time".
Last month, TESS reported that the EIS was warning of a mass exodus of teachers, driven from the profession by the unprecedented stress and additional workload created by the first year of the new qualifications.
Mr Jackson's speech today reads: "What happened this year cannot happen again. Never again must pupils and their teachers have to endure the stress and pressure they have this year.
"There is the issue of our S4 pupils experiencing the spectre of failure at an early stage and being the most tested generation of pupils ever - contrary to the principles of CfE."
The union leader was also due to raise concerns about the difficulty of providing a broad curriculum while preparing pupils for vital exams, saying that Education Scotland and the government must face up to these and the many other issues that "threaten the very foundation of CfE".
His speech continues: "It is with not a scintilla of pleasure that I repeat - if the voice of the EIS had been listened to and had a year's delay in the new examinations been allowed, I believe we, and more importantly the young people of Scotland and their parents, would be in a better place than we are now."
Mr Jackson's warnings were backed by the Scottish Parent Teacher Council (SPTC), which agreed that the CfE reform, designed to reduce assessment, had instead increased it to unmanageable levels for many pupils and teachers.
SPTC executive director Eileen Prior said: "Children have been assessed to death. We have had parents' groups contacting us about stress levels in teachers and pupils. We even know of one school which had to bring in counsellors to work with stressed-out pupils. This is not where CfE was supposed to take us."
However, Ms Prior said that although she sympathised with teachers, they also had to bear some of the blame for the mishandling of the new qualifications.
"If you look at the biggest issue, which has been over-assessment, there are a whole lot of factors in play here," she said. "Some of that has been created by a situation where teachers have lacked confidence so they have adopted a `belt and braces' approach, which I can understand, but nonetheless that has created more work."
Ms Prior said that local authorities, schools, teachers, the Scottish Qualifications Authority and Education Scotland all carried "some responsibility for where we are".
She added: "It's been a torrid time for pupils taking the National qualifications for the first time this year. It's been very stressful and their experience has been extremely difficult."
Mr Jackson was also expected to warn that Scotland's reforms would be stuck in an educational "cul-de-sac" unless politicians decided on their priorities and funded them properly.
His comments come after international educational reform expert Michael Fullan criticised the Scottish government for being too slow to bring about change since CfE was first launched more than a decade ago.
The government declined to give a direct answer when asked whether these pupils were the most tested ever. A spokeswoman said that the working group set up to monitor the implementation of the new qualifications would "encourage best practice".