President Mugabe expects to secure a two-thirds majority for his Zimbabwe African National Union Patriotic Front, or ZANU-PF. That party has been in power since Zimbabwe became independent in 1980.
Western observers say parliamentary elections in 2000 and presidential elections in 2002 were marred by widespread, and violent, voter intimidation.
The nation was plunged into political and economic chaos in 2000, when the government began seizing white-owned farms for redistribution to black Zimbabweans - to redress colonial-era injustices.
Mr. Mugabe and his supporters have charged that the major opposition party, Movement for Democratic Change, or MDC, is funded by Zimbabwe's wealthy white minority, and is a puppet of British Prime Minister Tony Blair.
Mr. Mugabe said, "Where [is] Blair, and who is he to us? I wonder, has the British public ever asked him why he is more concerned about Zimbabwe, and Zimbabwe alone, than any other country in Africa?"
Nelson Chamisa of the MDC says voters want Mr. Mugabe out of office.
"Mugabe is completely out of touch with reality," he said. "He keeps talking about Blair. Yet we have no Blair in this country. The election is between the MDC and ZANU-PF."
In Washington, U.S. State Department spokesman Adam Ereli said the United States is troubled by the ruling party's campaign.
“First of all, Zimbabwe hasn't invited civil society election monitors from neighboring countries," he said. "That's something to be regretted. They have not invited parliamentarians from the South African Development Community. And this, to us, is inexplicable and worrying.
Mr. Ereli also said the White House is concerned about Zimbabwe's denial of access for independent and international media outlets, including the Voice of America, to cover the election.