HARARE, Zimbabwe (CNN) -- As the hours ticked down toward the opening of Friday's balloting, Zimbabwean President Robert Mugabe showed no indication that he would give in to demands to postpone the runoff election despite his challenger's dropping out.
Robert Mugabe at a rally Thursday ahead of the presidential runoff vote.
Morgan Tsvangirai of the Movement for Democratic Change party dropped out of the race earlier this week, citing pre-election violence that he says has targeted opposition supporters.
But the government has said it is too late to take his name off the ballot.
A Mugabe aide told CNN that he expected the longtime leader to win re-election.
"When the process is done tomorrow, as a country, we (will) have a win that I think should include all the other players," said Bright Matonga, a spokesman for Mugabe's ruling ZANU-PF party. Watch preparations for Friday's election »
Matonga was hinting that Mugabe would be willing to share power with Tsvangirai's Movement for Democratic Change party.
"This is the reason why my president he says, 'Look, Zimbabwe is too big a cake to eat for ZANU-PF, bring everyone in.
"As a country ... we can mend bridges."
There has been a chorus of calls for Mugabe's government to delay the runoff, which his political opponents and world leaders have described as a "sham." Those calls include U.N. Secretary-General Ban Ki-moon and the Southern African Development Community -- of which Zimbabwe is a member.
A day before the scheduled runoff vote, Zimbabwe's opposition party warned of growing political genocide at the hands of government supporters, urging the world to intervene immediately before the situation became worse.
The MDC also accused Mugabe's ruling party ZANU-PF of planning to deploy fake polling agents on Friday to make it seem like Tsvangirai is taking part, despite his withdrawal from the race.
A government spokesman said the MDC was making "wild allegations."
The MDC said a build-up to genocide was evidenced by the arming of militia members and youth supporters of ZANU-PF, Mugabe's threats of war if Tsvangirai were to win the vote, and threats against those who vote for the MDC leader.
It said Mugabe's government had targeted the opposition and its supporters ever since the March 29 election, leading to genocide. MDC has also warned that Zimbabweans may be forced to vote for Mugabe on Friday, under the threat of violence. See a timeline of Zimbabwe's recent political turmoil »
Kerry Kay, the MDC's secretary for welfare, appealed to regional leaders "and indeed the world to take a stand now -- not in a week's time, now -- if we are to avoid the final stages of genocide." See pictures of the violence »
Meanwhile, a day before the runoff vote, MDC secretary-general Tendai Biti went free on bail after more than two weeks behind bars.
Biti had been jailed since June 12 on charges including treason, which can carry the death penalty. African and international leaders had criticized his arrest as a ploy by Mugabe to intimidate the opposition before the runoff.
The judge called the state's case against Biti weak and told him to appear back in court July 7, Biti's lawyer said.
Shortly after his release, Biti said he plans to complete the task his movement has started -- democratizing his country. Watch Biti walk to freedom and his reference to Nelson Mandela »
"Our people are suffering. Each second that was spent inside those prison cells strengthened me more and made me realize that we have to finish the business that we started, and the business of democratizing our country and making sure that our people have jobs and food," Biti said.
The MDC has said at least 86 of its supporters have been killed, 10,000 wounded and 200,000 displaced. ZANU-PF has accused MDC of exaggerating the situation, and has blamed its supporters for inciting violence.
Mugabe spokesman George Charamba has also chided news organizations for not reporting purported deaths of war veterans loyal to Mugabe, who he said had been "hacked to death" by MDC supporters.
Video shot recently at a hospital in Zimbabwe's capital city showed MDC supporters with injuries allegedly inflected by armed gangs that support Mugabe.
A gaping wound several inches long cut through a young woman's forehead, while discolored skin circled a man's nose as doctors try to save it.
Another man's lower back was a jigsaw patch of burned flesh. Deep purple bruises marked an "X" down his spine.
Harare's former mayor said the people shown in the video are innocent victims of someone "they thought was a hero." He did not elaborate, but clearly he was referring to Mugabe.
Eyewitnesses have said iron bars and sticks have been used as weapons for beatings and victims are forced to chant and recite slogans supporting ZANU-PF, according to a report released this week by Human Rights Watch.
One witness said that "if one failed to properly (recite) a slogan, then the beating would begin."
Citing "credible contacts" in Zimbabwe, Human Rights Watch researcher Tiseke Kasambala said people were being threatened with violence if they do not vote for Mugabe on Friday.
"They are being told to vote for Robert Mugabe tomorrow, and if they don't vote for Robert Mugabe, that there are more beatings and more torture to follow," she said.
Human Rights Watch has called on the 53-nation African Union (AU) to deploy monitors throughout Zimbabwe to report on human rights abuses and allow for democratic reform.
Kasambala praised South Africa, Kenya, Angola and Tanzania for putting pressure on Zimbabwe but said "more needs to be done." Watch Zimbabweans in South Africa discuss their country's political situation »
"Robert Mugabe should step down and agree to a transitional authority with the view of holding later elections, proper elections, under a conducive environment," she said. "And if he does not do so, they should threaten him with suspension from the AU.
In its report, Human Rights Watch said it believes Mugabe will hold on to power at all costs. He stated in a campaign rally that his ruling ZANU-PF party has "shed a lot of blood for this country," and that they would not give it up "for a mere X on a ballot."
"How can a ball-point pen fight with a gun?" Mugabe said.