Johannesburg - The national executive of South Africa's ruling ANC will discuss at a meeting this week whether President Jacob Zuma should step down as head of state, two senior ANC sources told Reuters.

There has been widespread speculation that the new leader of the ANC, Cyril Ramaphosa, and his allies are lobbying ANC members to oust Zuma as president in the coming weeks.

Zuma's presidency, tainted by corruption accusations which he denies, has tarnished the image of Africa's oldest liberation movement and seen the economy slow to a near-standstill.

Any sign that Zuma could step down early has tended to lift South African assets, including the rand currency.

Ramaphosa, who won a closely fought election to succeed Zuma as ANC leader last month, said in an interview broadcast on Sunday that the issue of Zuma's future would be dealt with "as time goes on".

READ MORE: Behind-the-scenes scramble to decide on Zuma's fate

Zuma's second presidential term ends in 2019 but he could be removed early through a motion of no confidence in parliament or following a meeting of the ANC's national executive committee (NEC).

The ANC's NEC has a meeting that starts on Thursday.

"Reference will be made to it," one of two sources said, when asked whether the NEC would discuss Zuma's removal at its meeting. The second NEC source confirmed Ramaphosa supporters intended for the meeting to address Zuma's possible exit.

It was not clear whether the NEC meeting would result in the ANC formally calling for Zuma to step down.

Zuma's future as president was not discussed at an NEC meeting last week, according to ANC Secretary General Ace Magashule.

Zuma, who orchestrated the removal of former president Thabo Mbeki in 2008 after succeeding Mbeki as ANC leader, has survived several no confidence motions in parliament and is still supported by a faction within the ANC.