JOHANNESBURG (AP) — South African President Jacob Zuma acknowledged Sunday that corruption and violence have marred the image of the African National Congress under his watch, but called on members to again support him to be the political party’s leader.

The ANC, once a liberation movement that started a century ago to fight apartheid, has been governing South Africa for 18 years and faces increasing criticism in this nation of 50 million people that’s the continent’s top economy. Some 4,000 delegates gathered Sunday for the start of the party’s Mangaung conference, being held in the city also known as Bloemfontein, and listened to Zuma offer occasionally candid comments about the party’s issues. Still, Zuma made promises and said his government remained on track to change South Africa, attempting to appeal to delegates who will decide whether Zuma or his quiet deputy Kgalema Motlanthe should take charge of the party. And while Zuma long has been trailed by corruption allegations and questions about his personal life, he remains the favorite among delegates to lead the party and likely become South Africa’s president after the nation’s 2014 elections.