The South African Democratic Teachers' Union (Sadtu) will be marching to Hoërskool Overvaal in Vereeniging on Thursday morning.
"We will be delivering a memorandum to the school governing body; the district officer will also be there," the union's Gauteng secretary, Tseliso Ledimo, told HuffPost.
The union will be joined by its affiliates, including the ANC (Sedibeng region) and Cosatu, and is expecting a representative from the school to accept the memorandum.
This is a continuation of protest action that has been happening outside the school since last week Wednesday.
This follows the Hoërskool Overvaal school governing body (SGB)'s successful court application to overturn a Gauteng education department decision to place an additional 55 pupils at the school.
While the department has deemed the application by the Vereeniging school's SGB a way to exclude black pupils, the school maintains there is not enough space to accommodate the additional learners.
This, despite the department's argument that provision had been made for new furniture and an English-speaking teacher to teach the extra children.
DA to lay charges after Facebook call to 'shoot Afrikaans children'
Democratic Alliance (DA) Emfuleni caucus leader Dady Mollo, along with other councillors, will be laying charges of incitement against social media user Aubrey Thamasanqa Mabele, for his posts about the protest at the school that called for people to shoot Afrikaans children.
In the Facebook post, he called on President Zuma to "give us the guns to defend our democracy", and aimed a call for "one bullet, een boerekind [one Afrikaans child]" at Hoërskool Overvaal.
The DA believes such behaviour is legally actionable.
"Incitement to cause violence based on language must not be condoned. The rights of all South Africans as enshrined in our Constitution must be respected," the party said.