Dinner ladies who work for catering contractors Scholarest and Caterhouse in Hackney, east London, are being underpaid.
The school cooks and catering assistants, who belong to the T&G union, say that they are not being paid the same rates as those who work directly for the council.
“The dinner ladies are under tremendous pressure after the Jamie Oliver programmes to deliver top notch nosh – but at rock bottom pay,” said Cathy Stewart, T&G convenor.
“To say they are angry is an understatement. They see little or no effort being made by the schools and the contractors to sort out their grievances.
“These loyal dinner ladies say it is about time they were shown some respect. That is why the T&G has now written to the schools to warn them action is simmering and, if nothing is done, it will boil over.”