Schools in England face closure next term after teachers voted to back a one-day strike over growing concerns that budget cuts are driving workloads up and forcing staff out of the profession.
Delegates at the National Union of Teachers (NUT) annual conference in Cardiff on Saturday agreed to use an existing ballot on funding to stage a one-day school strike in their challenge over budget shortages.
NUT general secretary Kevin Courtney said union members would be consulted before any strike was carried out, but that any action would be take place before August 31, before the NUT merges with the Association of Teachers and Lecturers (ATL) union — meaning schools could face a day of closure before the summer.
The vote came a day after Mr Courtney laid down an ultimatum to Education Secretary Justine Greening to increase government funding for schools by the Autumn Budget or risk strike action.
“There are places where the cuts are so bad and the degree of concern so big that strike action is a real possibility. We will consult with colleagues in the regions about the readiness of members to do this," Mr Courtney said.
“If Justine Greening announces the funding formula is changing to make things even worse in some areas, that would be very likely to raise the level of anger in those areas to a point where action will take place.”
Speaking in favour of the motion, James Kerr, a delegate from Lewisham in south-east London, said: “It's absolutely correct to say national strike action should not be off the table.”
During the conference, delegates heard that pupils were being forced to wear winter coats in under-heated classrooms, and NUT Surrey executive member Jackie Baker said she had evidence of a Spanish lesson being taught by a teacher who could not speak a word of the language.
The Government has said it has protected the core schools budget in real terms since 2010, with school funding at its highest level on record at more than £40 billion in 2016-17.