Jacob Zuma, leader of South Africa's ruling ANC party, has appeared in court to push for the dismissal of a corruption case that could stop him becoming president. Over 1,000 supporters demonstrated outside the high court in Pietermaritzburg singing, chanting and waving placards to denounce charges they say are politically motivated. The case is the biggest obstacle to the African National Congress leader succeeding President Thabo Mbeki. Mr Zuma denies the charges of corruption, fraud, money-laundering and racketeering but says he will step down if convicted. A long trial might mean Mr Zuma's case overlaps with a general election in 2009, which he would almost certainly win. Mr Zuma's lawyer, Kemp J. Kemp, argued in court that authorities had not followed constitutional procedures in the case. The ANC leader is accused of taking 783 bribes totalling more than £280,000 over a 10-year period. Most of the payments were connected to his former financial adviser Schabir Shaik who is serving a 15-year prison sentence for corruption. He is also accused of soliciting a £35,000 bribe from a French arms group for a massive arms deal arranged by South Africa in the late 1990s. Charges against Mr Zuma were dropped in 2005 for technical reasons although Mr Mbeki fired him as deputy president. Prosecutors brought charges again shortly after Mr Zuma beat Mr Mbeki last December to win the ANC leadership. Mr Zuma's supporters say the case is a conspiracy by Mr Mbeki's loyalists aimed at derailing his political ambitions.