Former presidents Nelson Mandela and Thabo Mbeki will be required, as "disciplined cadres of the ANC", to "lobby people quietly" ahead of general elections next year, ANC secretary general Gwede Mantashe said on Monday.

"It's a question of disciplined cadres of the movement doing what they should do," Mantashe told SABC radio news.

"There is no expectation [from] the ANC that they will play a prominent role as they did when they were presidents. But we are expecting them to talk to whoever they come across, lobby people quietly."

Mantashe's statements came as Mandela's office made it clear that he had retired from politics and would not campaign actively for the African National Congress ahead of elections next year.

Meanwhile, Mbeki loyalists are expected to form their own political party, but it is not known if Mbeki supports their movement.

Sapa