By Tom Gibb BBC correspondent in Sao Paulo

Brazil's presidential candidates are making their final appeals to voters on the last day of campaigning ahead of Sunday's general elections.

Opinion polls suggest that the left-wing Workers Party candidate Luiz Inacio da Silva, also known as Lula, is close to an outright victory.

Workers' Party supporters are hopeful

Government candidate Jose Serra is struggling to maintain a distant second place.

The Workers' Party candidate closed his street campaign this week with a trip down memory lane, to Sao Paolo's car factories where he rose to prominence as a union leader.

Lula led a series of strikes and protests against Brazil's military rulers in the 1970s and 1980s, which played a key part in pressuring for a transition to democracy.

According to the latest poll, Lula is just one percentage point away from getting the 50% of votes he needs on Sunday to become president.

Discontent

An outright win would represent one of the biggest victories for the left in Latin America in the last two decades.

Otherwise, Lula will have to face a second round run-off, in just over three weeks' time.

Serra, the government candidate, is now standing for 'change'

If that happens his most likely opponent will be Jose Serra, the government candidate.

The former health minister, he has been a loyal member of outgoing President Fernando Henrique Cardoso's governments for the last eight years.

But during the campaign he has had to run on a slogan of promising change - a sign of the discontent among voters at Brazil's economic stagnation.

Close behind Mr Serra is the former Communist, evangelical preacher, Anthony Garotinho, who was a popular governor of Rio de Janeiro.

A fourth candidate, Ciro Gomez, is now in last place, having lost most of the support he had just a few weeks' ago.

Campaigning will close with a final television debate between the four candidates.

Lula and Jose Serra have apparently made an agreement not to resort to personal attacks during the debate.