The country's main opposition, Movement for Democratic Change (MDC), wrote a letter to Zimbabwe's Electoral Commission (ZEC) last week saying the national voters' register was a shambles and needed an overhaul to remove people who had died.

ZEC chairman George Chiweshe - a former High Court judge - told a news conference on Thursday no register could be perfect and complainants had to provide evidence of any anomalies.

"The fact that there may be names of some dead people does not mean that the voters' roll is not a credible register as people die every day but the official evidence must be provided to correct that," he said.

President Robert Mugabe - who is seeking to extend his 27 years in power in March 2008 presidential, parliamentary and local government elections - denies opposition charges his ruling ZANU-PF party has cheated in three major elections since 2000 to remain in office.

MDC leader Morgan Tsvangirai has threatened to boycott the polls if his party becomes certain that Mugabe would rig them.

"If there are grey areas we ask everyone to help...," Chiweshe added, saying the commission had started dividing the country into wards and constituencies for the 2008 polls.

He said although the voters' roll was still open for registration, the commission would use a total of over 5.6 million voters, who were on the register by Tuesday to mark out the constituencies.

"All I can say is that our electoral system is as good as any in the region...and that you will never find a perfect voters' roll anywhere," Chiweshe said.

MDC officials were not immediately available for comment.

Chiweshe said although the voters' roll was still open for registration, the commission would use the more than 5.6 million voters who were on the register by Tuesday to mark out the constituencies.

"For the purposes of delimitation, we have to use this figure but everyone who registers will be eligible to vote," he said.

Under new constitutional changes agreed between Mugabe's government and the MDC, the number of seats in the lower house of parliament has increased from 150 to 210 and those in the upper senate have gone up from 66 to 93.

Critics say Mugabe has used tough laws and policing to keep the opposition in check in the face of a severe economic crisis they blame on his policies, and his ZANU-PF party routinely deploys police riot squads to crush anti-government rallies.

Mugabe, 83 and Zimbabwe's sole ruler since independence from Britain in 1980, blames Western pressure for the economic crisis and says he will win next year's elections fairly.