South Africa's President Thabo Mbeki has come under renewed pressure to resign after a High Court judgement.
It has been suggested he used his political influence to prosecute his rival Jacob Zuma.
Mr Zuma was fighting corruption charges in the High Court, but on Friday Judge Chris Nicholson dismissed the charges on technical grounds.
The court ruled that there was evidence that the investigation had been politically compromised.
Even within his own party, Thabo Mbeki is recognised as a lame duck president.
With less than a year to go before his term expires, he is now facing calls louder than ever to quit the national leadership.
The latest demands come from the more militant wing of the ruling African National Congress, which supports the party's leader, Jacob Zuma.
On Friday a High Court judge dismissed corruption charges against Mr Zuma, saying there was evidence of political interference in the investigation.
The judgement appears to vindicate Mr Zuma's supporters who have always claimed he was the victim of a political conspiracy led by Thabo Mbeki, who should now resign.
The judgement also appears to clear the way for Mr Zuma to become the ANC's candidate to succeed Mr Mbeki.
Now Jacob Zuma's supporters say it is time for the president to go or be forced from office.
But that would trigger early elections and senior ANC officials admit they are not as popular as they once were.
There is no suggestion that the ANC could lose the elections, but for a party used to near total dominance of government, any back-sliding in support would be politically damaging.