In the first serious attack on the mainline Scottish Executive policy, May Ferries, a past president of the Educational Institute of Scotland and a depute head in a Glasgow primary, cautioned council members that the reforms would produce more of the same.
"In my opinion, what we are in danger of doing is making no change at all," she said.
The EIS itself remains hostile to most of the proposals and reforms are unlikely to be implemented without some measure of union support.
It challenges annual progress plans and personal learning plans, rejects a national assessment bank that will replace 5-14 tests, and questions the Scottish Survey of Attainment if it identifies individual schools and pupils.
Ahead of today's deadline for responses to the Scottish Executive consultation on assessment, testing and reporting 3-14, GTC members from the primary sector reacted angrily to the proposals, hailed by ministers as a way to cut burdens on teachers and produce better information for parents.
Ms Ferries, backed by primary heads, said: "If we maintain a national assessment bank, teachers will get the message that they are not trusted and what they say about a particular child's progress cannot be trusted. As a General Teaching Council we have to challenge that." She argued that teachers were trained and experienced, knew their children intimately through working with them daily, and did not need the judgment of a one-off national test on a particular day.
The move to more formative assessment done routinely by class teachers did not need revised national tests that would simply add to the photocopying bill of primaries. When national testing was introduced, Ms Ferries recalled, teachers were unconvinced that pupils would not be pressured and that the curriculum would not be distorted by teachers teaching to the test. Target-setting had accentuated the concerns.
"Unfortunately, that prediction has proved to be true," she said, in the same week as ministers published the national 5-14 attainment results, that the Executive admits are flawed. These were widely used by the media to slam teachers' work in the basics, particularly in the first two years of secondary.
Ms Ferries said teachers should use their own class assessments backed by sampling under the Assessment of Achievement Programme (AAP) which would report on standards nationwide - but anonymously. The AAP testers would come in, give tests for which pupils were unprepared, and produce a national report.
"It doesn't say that East Renfrewshire children do really well and my children in Glasgow are rubbish," she stated. "I am quite happy for national standards to be monitored in an anonymous way like that."
Joan Robertson, a Fife primary head, said schools had been "curriculum-bound for so many years" and had to be freed from the restrictions. "We need to stand up and say 'we're not playing your games'," she stressed.
The proposed online national assessment bank would make no difference and teachers would still teach to the test. Like Ms Ferries, she believed in the AAP evidence.