The country’s president Jacob Zuma announced last month the government would bankroll the tuition but did not give details of how it would be funded.

A government report has said the plan is unaffordable. The details are expected to be in the country's budget out next month.

Finance minister Malusi Gigaba told reporters on Tuesday that costs estimates for the plan had been finalised and would be implemented over eight years.

In November, a presidential commission report urged the South African government to increase its spending on higher education to at least 1% of gross domestic product. This would be an increase from 0.75%.

Gigaba said: “The president found himself in an invidious position... It is about how to manage the process and implement it in a sustainable manner without having to breach the fiscal expenditure ceiling.”

“If the president had not acted this year to provide some funding it would have resulted in further protests,” he added.

In 2015, students protested across the country demanding free education.

The OECD warned that South Africa would need radical reforms to revive growth and called for a universal student loan scheme contingent on future earnings to make higher education more accessible.