A proposed tax on graduates will further exploit the working class, the SA Students' Congress (Sasco) said on Thursday.
Sasco opposed the African National Congress proposal because it embraced the notion that higher education was a private gain for students, its president Ngoako Selamolela said.
"Graduates from working class and poor backgrounds have a historic burden to redress the plight of their families...," he said.
"This resolution seeks to further exploit the working class such that they don't break from the poverty cycle."
Graduate tax worked against the logic of the implementation of free quality education, he said.
The ANC resolved at its elective conference in Mangaung last year to introduce a tax on graduates.
Conference delegates participating in the education and health commission resolved that consideration "must be given to a graduate tax for all graduates from higher education institutions". No other details were given.
The Democratic Alliance said a tax on working graduates would be unfair.
"It would mean an extra payment on top of their income tax, at a time when many are struggling to make ends meet," DA Youth federal leader Makashule Gana said in a statement.
"Under these circumstances, a graduate tax could actively discourage students from entering tertiary level education."
Gana said many students were still battling to pay off student loans.
Student loan debt of around R3 billion in 2009 had since risen.
There was currently no guarantee that a graduate would get work, he said.
"Instead of a tax, we need a youth wage subsidy to help young people find work when they finish school.
"We must not crush the spirit of young people with taxes," he said.