Staff at City of London Academy in Bermondsey were set to strike today, Thursday.
A number of teachers were expected to walk out in a dispute over the way their performance is monitored at the school.
The school in Lynton Road was expected to remain open to sixth form, Year 10 and Year 11 students – but close to children in Year 7, 8 and 9 for one day only.
A teacher, who wished to remain anonymous, said it was the first time staff at the school had taken strike action of this kind.
A spokesperson for the City of London Corporation said they were “disappointed” the strike was taking place.
“This comes after extensive negotiations and continuing efforts on behalf of the academy to reach a resolution,” said the spokesperson.
“Our academy requires teachers to follow a support programme to improve their practice. We want all our teachers to benefit from the advice and support of other excellent staff at the school in order to enable them to teach consistently well.
“We are working hard to resolve this dispute as quickly as possible.”
The spokesperson did not confirm how many members of staff would be striking.
Parents are said to have been informed of the strike at 4pm on Tuesday.