South Africa's respected former Finance minister Pravin Gordhan called Tuesday for President Jacob Zuma to resign, stepping up pressure on the embattled leader.

Mr Gordhan joined a growing number of activists in the ruling African National Congress (ANC) along with anti-apartheid veterans and business leaders who have appealed for President Zuma to leave office.

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Mr Gordhan was seen as a bulwark against corruption until he was sacked in March in a government reshuffle that triggered unprecedented criticism from senior ANC figures including President Zuma's deputy Cyril Ramaphosa.

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"I think the president should move aside and let somebody take over this country and reset the course," Mr Gordhan said in a debate to commemorate Nelson Mandela Day.

Mr Gordhan remains widely popular among many South Africans but is not seen as a potential presidential candidate.

President Zuma has been engulfed by graft scandals and has faced several humiliating court rulings while grappling with record unemployment and a sluggish economy.

On August 8, parliament will vote on a motion of no confidence in President Zuma, which he is likely to survive due to the ANC's majority.

READ: South Africa MPs to defy ANC over Zuma no-confidence

Opposition parties have campaigned to have the vote conducted by secret ballot to encourage disaffected ANC lawmakers to vote against him.

The Constitutional Court has directed the parliament Speaker, President Zuma-loyalist Baleka Mbete, to make a ruling on the matter before the vote.

President Zuma, 74, is due to step down as head of the ANC party in December, and as president ahead of the 2019 General Election.

The vote for the ANC slipped to 55 percent in last year's local elections — its worst-ever election result.