President Kgalema Motlanthe urged South Africans on Saturday to register to vote in next year's presidential election, which many are billing as the most important since the end of apartheid.

Motlanthe cited the high turnout in the recent US election as he signed himself up and led the way for the thousands of South Africans expected to turn up at some 20 000 voting stations in a massive weekend registration drive.

It was "crucial that South Africa's young and old register to cast their ballot next year," independent radio station 702 quoted Motlanthe as saying.

The 2009 election, for which no date has yet been set, is expected to be the most dramatic since Nelson Mandela became the country's first black president.

The monolithic ruling Africa National Congress (ANC) party, founded as a liberation movement in 1912, is facing a challenge from dissidents who broke away from the party after a national convention held last weekend.

Jacob Zuma seized control of the ANC from Thabo Mbeki during the party's conference last December, and his allies in the leadership forced Mbeki to resign as president in September just months before the end of his second term.

The ANC was out on early on the campaign trail to shore up support, with Zuma expected to visit registration stations in the Western Cape where the dissidents have gained a lot of ground.

A survey of 4000 people by South Africa's Independent Electoral Commission (IEC) showed 80 percent of those intending to register ranged from "very interested" to "slightly" interested, the Saturday Star reported.

The IEC website crashed after more than 180 000 visits and the organisation has decided to extend registration time by four hours.

In 2006, a total of 21 054 957 South Africans aged 18 or above registered to vote with women accounting for more than half that figure, according to the IEC.

Sapa