John Swinney has been warned against inflicting "even more damage" on Scotland's pupils after it emerged he is planning to scale back next year's exams.
Mr Swinney is expected to cancel next year's National 5 exams, with around 80,000 pupils awarded their certificates on the basis of coursework only.
The Deputy First Minister is also considering plans to scale back Highers, the gold standard of the Scottish education system, basing them on a shorter school year with fewer areas of some subjects being covered.
But parents' group Us For Them Scotland, which helped force Mr Swinney into a U-turn on reopening schools, said children could not afford to have "their exams disrupted again."
In a letter to the Education Secretary, the group said it was unfair to leave them "hanging this way" and urged to make an "unequivocal statement" the 2021 exam diet will go ahead as normal.
The Scottish Tories said Mr Swinney's "plan A" must be to press ahead with the exams and "exhaust all avenues before scrapping them."
Mr Swinney is expected to outline his plans before the October school holidays, which starts in three weeks, but the Conservatives urged him to make an urgent Holyrood statement.
He is determined to avoid a repeat of this year's exams fiasco, which saw teachers estimate grades but the SQA revising these down for around 75,000 pupils.
The controversial moderation system, which put the poorest pupils at a disadvantage, resulted in an angry backlash and their original grades eventually being restored.
Mr Swinney has said a report into the debacle, due by the end of the month, would inform his decision on the 2021 exams, with “extensive feedback” also being gathered by the SQA.
His decision will take into account the months of classroom time pupils have already lost and the potential for schools to close again during future local and national lockdowns.
But Jo Bisset, of Us For Them Scotland, said: "We cannot afford for children to have their exams disrupted again, and parents want certainty on this matter now.
“UsForThem Scotland would like to see an unequivocal statement from the Scottish Government that the 2021 exams will go ahead as normal, so that pupils can start preparing now for such a crucial juncture in their life.
“Anything less than that will risk causing even more damage to the future of a generation of pupils.”
Speaking ahead of a Tory debate at Holyrood on Wednesday, Jamie Greene, the party's Shadow Education Secretary, urged the SNP to “make every effort” to save National 5 and Higher exams.
He said: "Nobody is pretending it will be easy, but it must be our central goal to give pupils a return to as much normality as possible. We cannot afford to fall into another mess like last year.”
A Scottish Government spokesman said: "Our ambition is to run a 2021 examination diet, however there remains a risk of further disruption for learners and schools, or more widely across the country."
He said officials were examining "appropriate contingencies" and Mr Swinney would "provide clarity" before the October holidays.