Zimbabwe's opposition, along with international observers, is voicing growing concerns about this weekend's scheduled elections.
This is despite government assurances that the ballot will be free and fair.
Both the opposition Movement for Democratic Change and independent challenger Simba Makoni have accused President Robert Mugabe and his ZANU-PF party of trying to rig the ballot.
They say this will be done using security services to intimidate voters and by depriving Mugabe opponents of air time.
The US State Department has criticised what it called ‘significant shortcomings’ in the electoral process, while Amnesty International said the police were intimidating opposition supporters.
MDC Secretary General Tendai Biti said President Mugabe, who has ruled since Zimbabwe's independence from Britain in 1980, was reneging on agreements about the framework for the elections reached during earlier talks.
The government has caused consternation in opposition ranks by allowing police into polling stations - ostensibly to assist any voter who is illiterate or infirm.
The US, which imposed sanctions on Mr Mugabe and his inner circle after he allegedly rigged his 2002 re-election, has been barred from sending vote monitors to Zimbabwe for Saturday's election.
With European Union observers also kept off the invite list, the process will instead be monitored by organisations such as the African Union, as well as representatives from China, Iran and Russia.
