Liberia's leading opposition candidate says he is pulling out of next week's presidential run-off election, saying he believes the vote will not be fair.

Winston Tubman told a news conference Friday that he will not take part in the November 8 race, and urged others to boycott the poll.

He says his party, the Congress for Democratic Change, believes the election process is flawed and will not grant legitimacy to the vote.

A boycott would mean a guaranteed victory for the country's ruling party and incumbent President Ellen Johnson Sirleaf.

Electoral officials say the vote will go ahead as scheduled despite the opposition boycott.

The opposition CDC alleged that electoral commission chairman James Fromayan manipulated vote counts from the first round to give the president the lead. Fromayan resigned Sunday, saying he did not want to give the opposition an excuse to boycott the run-off.

Election observers from the Carter Center and the Economic Community of West African States say problems in last month's first round of voting did not affect the outcome.

Tubman finished second in that round, and he is on ballot papers that have already been printed for the run-off.

President Sirleaf says her opponents are trying to confuse voters by pretending to boycott the run-off election

while actively campaigning behind the scenes.