Parents say they are angry about plans to increase pupil numbers at a Coventry school where the children are taught in corridors due to the lack of space.
The city council wants to increase the intake of four and five-year-olds from 75 to 90 pupils at John Gulson Primary School from September.
It said two mobile classrooms with extra toilet blocks would be provided.
The Parents Action Group said that did not address the current lack of space and a new school building was needed.
Parent protest
The school in George Street currently has about 500 pupils and Coventry City Council said rebuilding it would cost more than £8m.
It previously told parents it was looking into other design options to increase classroom space and said it had to provide more than 400 extra primary school places across the city within the next two years.
Naima Ali-Khan, from the Parents Action Group said parents planned to protest about the inadequate teaching facilities outside the school gates on Wednesday and would also hand a petition in to the council calling for a new school building.
Parents previously held a protest outside the council offices in December.