President Kgalema Motlanthe on Friday called for tolerance during the campaigning for the upcoming elections, as the ruling party faces a tough challenge from a breakaway party.

Motlanthe made the remarks in his state of the nation address to parliament after nine ANC supporters were injured while campaigning last weekend.

The opening of Parliament 2009

"The robustness of our political engagement during this season of electoral contest, which we all agree should be dignified and peaceful, is the surest guarantee of the continued survival and deepening of our democracy," Motlanthe said.

"Naturally the uncertainties of a political transition can pose more questions than there are currently answers," he said.

"In a strange quirk of fate, many aspects of our constitutional order have been tested in the recent past, and every one of them has passed the test to reveal a democracy that is exceptionally resilient," Motlanthe added.

Motlanthe was expected to announce a date for South Africa's fourth national elections since the end of apartheid in 1994.

ANC leader Jacob Zuma is the frontrunner for president, but deep divisions have emerged after the party sacked former president Thabo Mbeki in September.

The dissent led to the creation of a breakaway party, the Congress of the People (Cope), which is challenging the ANC in the election.

Cope has also complained of ANC members blocking their supporters from entering rallies, and the fierce competition has led to heated language, including messages from the ANC youth league to "kill for Zuma."