The spectre of the infamous millennium exams debacle is hanging over the introduction of the new National qualifications, shadow education secretary Kezia Dugdale has suggested.
The first students to sit the exams were being treated like "a generation of guinea pigs", she said.
"There is a sense of, `Are we heading towards another SQA-type scandal of 14 years ago?'" said the Labour MSP, referring to the exam reform in 2000 that caused thousands of wrong or late results and led to 147,000 certificates being rechecked.
The Scottish Qualifications Authority has received significant criticism in recent months over the implementation of the new Nationals, particularly over a lack of clarity in the information provided to teachers and schools.
Ms Dugdale, the daughter of two teachers, said she had been meeting school staff and maintaining close contact with the Scottish Secondary Teachers' Association to gauge the scale of concern.
"One particular teacher (in Glasgow) told me that a textbook for one of the courses she was teaching wasn't available yet," Ms Dugdale told TESS. "So if she didn't have the textbook, how could she possibly prepare the kids for a prelim that was to prepare them for an exam they would be sitting within the next calendar year?"
Ms Dugdale, who took on the shadow education job last June, said: "I think it's possible that we could let down the pupils who are about to sit these exams for the first time, and that's the parallel with what happened back in 2000.
"There was a year of pupils who, through no fault of their own, found themselves heavily disadvantaged by an education system that's supposed to support and help them. And that's where the fear and concern is - it does feel very much like we have a generation of guinea pigs that are being asked to road-test a new curriculum, and parents, teachers and pupils alike are unsure as to whether the appropriate safeguards are there to protect them.
"I don't think that's inflammatory, I don't think that's going over the top - I just think that's a fact."
Ms Dugdale also attacked the recently announced Scottish government policy to provide all P1-3 children with free school meals. She said that although free lunches were a good thing, they were "absolutely not a priority" because the poorest children were getting them already.
She claimed the reality of the meals provided would not be "Jamie Oliver's panacea of. freshly home-cooked meals (prepared) onsite by grannies sitting there chopping up carrots".
"This is factory-made meals that will be reheated in microwaves in schools," she said. "There's no assessment been made of how you can provide properly, nutritionally balanced cooked meals on the school premises in every part of the country."
Ms Dugdale added that it would make more sense to put the money into childcare and breakfast clubs.
Minister for learning Alasdair Allan said he was "hugely disappointed" to hear of Ms Dugdale's comments, which he said risked undermining the confidence of teachers, students and parents in the approach to the final stages of the new qualifications.
He added: "It is crucial that we support their successful delivery and recognise the hard work going on across the country to ensure pupils do as well as possible. I have kept parliamentary colleagues updated on the improvements and the significant support given."
Mr Allan added that no concerns had been raised at the point of the last briefing in December, nor since then.
"The report by the parliamentary committee in 2000 set out clearly the reasons for that situation. They are entirely separate from and have no bearing on the significant progress made to implement Curriculum for Excellence and the National qualifications," he said.
A spokesman for the government added that it was "simply wrong" to suggest that free school meals would not tackle poverty and inequality.