Michael Gove has been accused of "shamefully neglecting" the nation's children and pushing ahead with damaging education reforms.
Pupils are suffering as a result of the education secretary's policies, which have left teachers' morale at "rock bottom" with many choosing to leave the profession, according to Dr Mary Bousted, general secretary of the Association of Teachers and Lecturers (ATL).
She accuses Gove of bringing the government into disrepute by introducing reforms which ignore expert opinion and have no democratic mandate.
In her speech to ATL's annual conference in Liverpool, Dr Bousted will say that it is her "duty to castigate the man who is undermining everything we stand for".
Dr Bousted says that successive education secretaries have presided over "turbulence" in the education system, and teachers are used to dealing with the changes.
But she added: "Now, in 2013, every aspect of the curriculum you teach, the qualifications you prepare children to take, are under attack and review.
"Michael Gove should take heed. When the changes come so thick and fast, without time for consultation or even consideration, when the changes are so wrong-headed, so damaging to children's education, then the morale of the profession plummets."
Dr Bousted uses her speech to warn Gove that through his "unjust, incessant and unfair criticism of teachers and lecturers" he has ruined their pride in their professionalism.
"What is even worse is that you have shamefully neglected the children and young people in schools and colleges at present," she will tell the conference.
"What are they to think of you who have shown so little care of them, of the qualifications they work so hard to attain and of their future life chances? Your constant meddling, changes and U-turns make life impossible for today's youngsters."
The government's new curriculum looks forward to a "rosy past", Dr Bousted argues, and will fail to prepare today's children for life in the 21st century.
And she accuses Gove of doing the "hokey cokey" with the subjects studied in secondary schools.
"Young people have just one chance, in each life time, to receive a broad and balanced education," Dr Bousted says.
"The subjects in the secondary curriculum should not be treated like the hokey cokey - arts, drama, music, computer science, in, then out, then shaken all about.
"Unfortunately, Michael, that is just what you have done. Shaken it all about. Young people, their parents, their teachers, their potential employers, society at large, deserves much better than this."
Dr Bousted's speech also accuses the government of forcing schools to become academies against their wishes, and claims that it is "paving the way for the wholesale transfer of our schools to the private sector if the Conservatives are in office after the next election."
"The government rushed to legislate to allow schools to choose to become academies," she says.
"But where is the democracy in forcing it on parents and the local community when the policy has never been approved by Parliament?"
Dr Bousted adds: "Michael Gove is bringing government into disrepute by instigating policies that have no democratic mandate, and by ignoring all expert opinion."
A Department for Education spokeswoman said: "These accusations couldn't be further from the truth.
"For too long standards in our schools have been declining. We need to make sure we have an education system that is robust and rigorous, with exams and qualifications that match the world's best. This is surely something the ATL should be applauding.
"Mary Bousted claims that the academies programme has no democratic backing - this is nonsense. It was passed by Parliament and has been hugely popular, with more than a third of all secondary schools choosing to convert to enjoy the freedoms and autonomy it brings.
"We will not stand by and let children fail. We are improving under-performing schools by matching them with sponsors who are turning them around in their hundreds. We are driving up standards by introducing a world class curriculum and we are overhauling our qualifications system to keep pace with the demands of universities and employers."