Headteachers today overwhelmingly backed a national walkout over the Government's public sector pension plans.
Members of the National Association of Head Teachers (NAHT) voted in favour of strike action - a move which is likely to close thousands of schools and affect millions of children.
The union says the Government's plans will leave teachers working longer, paying more and receiving less when they retire.
Turnout for the ballot was 53.6%, with 75.8% in favour of strike action, the NAHT said.
Members of the NAHT are now likely to take part in the TUC's day of action on 30 November.