The TES internet staffroom has been inundated by messages from teachers who believe the Association of Teachers and Lecturers should have been more discreet about its members' decision to give up a day's pay to help with the school's budget crisis.
Teachers accused the union of belittling the profession and engaging in crass gesture politics. One ATL member said she would resign from the union over the issue.
The school has a budget deficit of pound;38,000 and is planning to cut a number of support staff jobs at the end of term.
Jane Stevenson, an ATL member who is a teacher governor at the school, said: "As teachers we decided to do something to improve our situation. In effect, we as professionals are funding what the Government is depriving children of."
An ATL spokeswoman said that the union did not regret its actions.
"We felt it was right to show the lengths that our members are going to in order to highlight the funding crisis," she said.
The incident is one of a steady stream of reports in local and national papers which are keeping the funding crisis in the public eye.
Coulsdon high school in Croydon has told parents that one afternoon's lessons per week will be axed from September because of a pound;300,000 deficit.
In Bristol, the National Union of Teachers has warned that a lack of money could force schools to operate a four-day week next year.
A survey by Conservative local government leaders found that two-thirds of councils will make teachers redundant and nearly one in 10 schools has set deficit budgets. Reports in the Plymouth Evening Herald suggest that 70 school staff face redundancy, while in Brighton, schools face a total deficit of more than pound;6 million.
"The TES" is monitoring the funding crisis. If your school faces problems please contact email@example.com