Finance Minister Tendai Biti, who is also the Movement for Democratic Change (MDC) secretary general, expressed his parties concerns over voter registration and violence issues, saying: "There's massive challenges with the voter registration exercise that is taking place."
"It's the ordinary hygiene issue of the election, the integrity of the election, we are talking about," he added.
General elections expected in July should end a shaky coalition government between Tsvangirai's MDC and President Robert Mugabe's Zanu-PF party.
Biti said there was need to "vaccinate" the vote against violence as "self evidently in the last few weeks there have been signs, sprouting shoots of violence … potential replication of the 2008 status quo."
The MDC has since the start of the year recorded over 120 incidents of violation and abuse of individuals, he said.
These and other concerns such as inequitable access to the public media by the MDC, have been raised with the regional bloc Southern African Development Community (SADC).
An SADC security organ comprising three presidents met in Pretoria on Saturday to discuss Zimbabwe, and South African President Jacob Zuma said the grouping "will take necessary action" on the issues raised by the MDC.
Biti said voter registration is underfunded and inaccessible to many citizens.
"The Zimbabwe Electoral Commission is unable to roll out a mobile voter registration," he told a news conference in Pretoria.
Two thirds of the six-million voters on the roll are dead, said Biti, discussing irregularities with the crucial list.
"But unfortunately those four million who are dead have had a tendency to resurrect on election day."
Furthermore state security forces have been used to up the stakes in Mugabe's favour, Biti claimed.
'Stop or exacerbate the crisis'
"The state machinery is busy reinforcing and mobilising soldiers and other members of the armed faction of the state to actually register, to the detriment of ordinary civilians."
"Ordinary people are not registering to vote," he added.
Zimbabwe's security forces are known to be pro-Mugabe.
Biti further expressed concern at statements by his peers in the coalition government that Western observers will not be allowed to monitor the vote.
"As a country we should have nothing to hide … (and therefore) anyone whether from Timbuktu, Beijing or Bali … you should be allowed to come."
The upcoming polls were "the most important" since a vote just after independence in 1980, he added.
"It's a make-or-break election as far as the ordinary average Zimbabwean is concerned," he said.
"This election will either stop the crisis, bring a legitimate and sustainable outcome or will further exacerbate the crisis."
Mugabe and Tsvangirai were forced to share power after deadly polls in 2008.
But reforms have been bumpy and a failed vote would mean "all the four years that we have spent in the unity government would have been a waste of time and we will be back to square zero," said Biti.
Zimbabwe holds a referendum next Saturday to decide on a new constitution. SADC is deploying observers to the referendum on Sunday.
Though the cash-strapped country had raised enough money for the upcoming vote, it asked for aid from the United Nations for the general polls, said Biti.
"Clearly Zimbabwe doesn't have sufficient funds to hold both the referendum and the election," he said. "Things are excruciatingly tight."
Biti said there were also concerns about the "morning after" the vote.
"What mechanisms are there to ensure that Zimbabweans will vote freely for their next leader, and that the next leader will be allowed to take up the seat of office?" – AFP.