Greenwich Council said it remains in discussions with the union and understands that 11 schools across the borough may be affected by strike action.
A spokesperson said: “We respect the right of unions to take industrial action.
“However, the best place for children is in the classroom, and we hope for constructive discussions to minimise disruption to pupils.”
Greenwich Council said the pay gap has its roots in national agreements dating back to the abolition of the Inner London Education Authority in 1990, when teachers retained Inner London pay but support staff did not.
While teachers’ pay is nationally protected, councils have discretion over support staff weighting.
