South African President Jacob Zuma has brushed off suggestions that an anti-corruption report criticising a state-funded security upgrade to his home will damage his party ahead of elections.

The controversy follows a report published in March by prosecutor Thuli Madonsela, which said Zuma had "benefited unduly" from the "excessive" $23m upgrades to his Nkandla home.

The bill included a chicken run, amphitheatre and swimming pool.

"It's not an issue with the voters," said the president on Monday, who is expected to be voted in for a second five-year term by parliament after Wednesday's election.

Zuma, whose personal approval rating has declined seven points, to 58 percent, since the publication of the report, said only the "media and the opposition" were concerned with the issue, the Reuters news agency reported.

The president's party, the African National Congress (ANC), has been in power since the end of apartheid in 1994.

Despite high unemployment and widespread disenchantment with the government, it is still expected to win almost 64 percent in the election, down only slightly from nearly 66 percent five years ago, a poll published in South Africa's Sunday Times said.

Zuma defended the upgrades to his home and said the accusations against him were unfair given the importance of protecting any head of state.

"My homestead was burned twice during violence and secondly my wife, criminals came, raped my wife," he said, referring to incidents when he was a provincial minister from 1994 to 1999.

Zuma has been criticised over the Nkandla scandal by senior members within the ruling ANC and by swathes of angry youths, who carry out almost daily protests in townships over poor government services and a lack of jobs.

However, the ANC's legacy as the party that freed millions of blacks from apartheid ensures it maintains a fiercely loyal support base, and even many of its detractors would rather not vote than support its opponents.

Source: Agencies