Retired Archbishop Desmond Tutu is one of South Africa's leading moral lights.

The Nobel Laureate was one of the champions of the nation's struggle for democracy.

His public avowal that he won't vote for the African National Congress in May's elections is a telling swipe.

(SOUNDBITE)(English) RETIRED ARCHBISHOP DESMOND TUTU SAYING:

"Nobody ever expected that we were going to have a paradise overnight but we could have shown that we intend walking the path that is going to ensure that we try to narrow the gap as much as it is possible."

The ANC is still expected to romp home with a comfortable win.

But there's growing public anger over corruption within the administration of President Jacob Zuma who's seeking a second five-year term.

Tutu's said the ANC under Zuma has failed to fill the shoes of Nelson Mandela and others who fought to end apartheid.