“There’s massive challenges with the voter registration exercise that is taking place,” said Tendai Biti, who is also the Movement for Democratic Change (MDC) secretary general.

“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.

But 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 the South African capital 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.

“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 lamented.

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.

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 2007.

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.

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.”