Education Secretary Michael Gove has criticised union hardliners "itching for a fight" ahead of Wednesday's public sector strikes.
In a speech at think tank Policy Exchange, Mr Gove warned that 90% of schools would be closed by striking teachers and appealed for them to think again.
He said union militants wanted families to be inconvenienced.
But the PCS union said the public supported the strikes.
It said: "A BBC poll released today shows overwhelming support for the strike and overwhelmingly people feel that Gove's government is mishandling the economy. Gove's speech smacks more of desperation than opinion and will fall on deaf ears."
The strike over pension changes in the public sector could involve up to two million people.
Mr Gove said of militant unions: "They want mothers to give up a day's work, or pay for expensive childcare, because schools will be closed. They want teachers and other public sector workers to lose a day's pay in the run-up to Christmas.
"They want scenes of industrial strife on our TV screens. They want to make economic recovery harder - they want to provide a platform for confrontation just when we all need to pull together."