Michael Gove is urging teachers to reconsider taking part in a national strike on Thursday.
The Education Secretary is set to say those taking part in the walkout are putting their own pay and pensions ahead of children's education.
In a speech to the Education Reform Summit in central London, Mr Gove is expected to stress that the Government's educational reforms are necessary, and that "our status quo" has not been good enough.
"We can't and we mustn't keep going backwards - and failing the poorest above all," he is due to say.
Union leaders said they were "overwhelmed" by support after a strike by public sector workers caused widespread disruption.
David Cameron, Michael Gove and other Government figures depicted in a variety of unflattering manners by striking public sector workers.
Hundreds of schools are to close tomorrow as teachers join strike action. Find out what schools in your area are affected.